Enhancement & Care of Gemstones

Unfortunately, gemstones don't come out of the ground ready to be set in jewellery. Raw crystals from the earth are usually called 'rough gemstones' (or just 'rough') and this is actually very apt - rough gems can look pretty rough!

To make sure each gemstone reaches its full potential, lapidaries and jewellers employ a variety of techniques. Some of these, like cutting and setting, are immediately visible, while others such as enhancements or treatments remain relatively unknown despite being used for thousands of years. Practiced in India for over 4,000 years, the earliest known gemstone enhancement is heating a gem to improve its colour. Oiling to improve a gem's clarity is another ancient technique that has been used for over 2,000 years.

Not all gemstone enhancements can trace their origins to antiquity, some such as the beryllium bulk diffusion of Sapphires and the physical vapour deposition (PVD) of Mystic Topaz, are the result of more recent innovations. In the gem industry, the term 'enhancements' sometimes exclusively refers to traditional techniques that are so common they are seldom mentioned, reserving 'treatments' for more modern methods. The problem is that this is not universal - both terms are often used to refer to the same processes.

Regardless of what they are called, all gemstone enhancements simply accentuate the beautiful end results of gemstones natural formation. Defined as any process other than cutting that improves a gem's appearance (e.g. colour, clarity, phenomena etc.), durability, value or availability, with the vast majority of gems enhanced in some way, these processes have become an important part of the modern gemstone industry. Given the prevalence of enhancements, one term that still has a universal meaning is 'natural'. A 'natural' gemstone is one that has not been enhanced or treated in anyway.

Enhancement Disclosure

The World Jewellery Confederation (CIBJO or Conf'd'ration Internationale de la Bijouterie, Joaillerie, Orf'vrerie, des Diamants, Perles et Pierres) is the organisation that records accepted trade practices and nomenclature for the global gem and jewellery industry. Under their guidelines, all jewellers should be aware of how the gems they sell are enhanced, disclosing this information to their customers. In a world where many enhancements are very difficult to detect (or even undetectable) using standard gemmological equipment, enhancement disclosure can be confusing for the consumer. Our threefold enhancement policy is designed to keep things simple, providing you all the information you need to make informed buying decisions:

  • We include a statement on every customer invoice advising you to always assume enhancements when purchasing our gemstone jewellery, directing you to this page for more information on what enhancements may have been applied to the gemstones you have purchased. This is not to say that every gem we sell is enhanced, we also sell 'natural' gemstones, it's just easier if you work off this assumption.
  • We only knowingly accept enhancements that are permanent with normal wear. The only exception is Emeralds, whose beauty is enhanced and easily maintained by oils or polymers. We get our information on gem enhancements from universities, gem laboratories, trade associations, regulatory bodies, professional journals, books, the internet as well as individual experts.
  • Gemstone enhancements can make gemstones more beautiful, affordable and even more durable. Despite this, some gems require special care. While this section includes some simple gem grooming do's and don'ts, the big table below shows the potential enhancements applied to each gem variety, their frequency, as well as any special care instructions.

Gem Care Do's & Don'ts

While one of the defining attributes of gemstones is durability, much as you wouldn't slip on Prada stilettos for a lively game of beach volleyball, following a few simple do's and don'ts will make sure your gemstones last for generations.

  • Do keep your gemstone jewellery in the separate compartments of a jewellery box or in cloth pouches, always storing your gem necklaces flat. When storing chains in pouches, leaving the catch just hanging out will reduce tangles.
  • Do gently wipe your jewellery with a lint-free cloth after each wearing to remove oils and salts.
  • Do periodically clean your jewellery. Rings can easily collect dust, soap and grime behind the setting if you wear them regularly. While a dirty gem will loose colour and brilliance, most gemstones are easily cleaned by soaking them in water with a little gentle soap. If especially dirty, use a very soft toothbrush to gently scrub behind the gem. Organic gems like Pearls or Amber should only be wiped clean with a moist cloth.
  • Do pull out a watch's crown to the setting position when storing them to save the battery.
  • Do listen to your jewellery. If you think a gem is loose in its setting, very gently tap it close to your ear. If you hear a 'rattle' the gem is definitely loose and will need to be repaired.
  • Do ask the seller about how to clean and care for the jewellery you have purchased.
  • Do take the time to read the following table.
  • Don't put on your jewellery before using cosmetics, hair spray or perfumes. Some gemstones are porous and may absorb chemicals that can discolour them.
  • Don't ever remove your jewellery by pulling on the gems as this can loosen their settings resulting in them falling out!
  • Don't ever store your jewellery in heaps as your gems can scratch each other. As almost every gemstone is harder than gold, silver or platinum, even the finish of your jewellery can be damaged if you throw your jewellery in a heap.
  • Don't wear your jewellery when playing sports, doing housework or anything else that risks impact, exposure to chemicals or heat. Simply exercise common sense.
  • Don't use a commercial cleaning solution until you have checked it is suitable for your gem.
  • Don't use ultrasonic or steam cleaners for every gem. Check the table below to see what gems are OK for these mechanical cleaners, but as a general rule, when in doubt, leave it out. Ultrasonic cleaners transmit vibrating energy waves to knock dirt off the jewellery, while steam cleaners use jets of steam to blast dirt off jewellery.
  • Don't use silverware polish to clean sterling jewellery. Apart from getting lodged in nooks and crannies, it is not gem friendly.

A

Agate (Agate)

Treatment None or dyeing or heating explanation Dyeing and heating is often used to improve the colour Care Instructions Do not expose to temperature shocks Steam Cleaning No Ultrasonic Cleaning No

Agate (Ayrshire Agate)

Treatment Impregnation with colourless resin explanation To stabilise the agate before carving into sculptures. Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning Yes

Agate (Purple Glitter Agate)

Treatment Surface treated with titanium, coated explanation Commonly used to produce unique colors Care Instructions Rinse in a bath of distilled soapy water, pat dry with a paper towel, and then briefly blow-dry. Steam Cleaning No Ultrasonic Cleaning No

Agate (Violet Agate)

Treatment Dyeing explanation Used for colour enhancement Care Instructions Do not expose to acids Steam Cleaning Yes Ultrasonic Cleaning Yes

Agate (Blue Agate, Pink Agate)

Treatment Dyeing explanation Used to improve the colour Care Instructions Clean with warm soapy water and a soft cloth. Steam Cleaning No Ultrasonic Cleaning No

Agate (Green Agate, Multicoloured Agate)

Treatment Dyeing explanation Dyeing is often used to improve the colour Care Instructions Do not expose to temperature shocks Steam Cleaning No Ultrasonic Cleaning No

Agate (Blue Agate, Orange Agate, Red Agate)

Treatment Dyeing explanation Generally used to improve/strengthen the colour or to create unique colours. Care Instructions Clean with warm soapy water and a soft toothbrush. Do not use aggressive chemicals or cleaning fluids, especially bleach or acids, as this could damage the surface. Do not expose to extreme heat. Store individually to avoid scratches. Steam Cleaning No Ultrasonic Cleaning No

Agate (Mandarin Agate, Purlpe Agate, Raspberry Agate, Yellow Agate)

Treatment Dyeing explanation Used for colour enhancement Care Instructions Do not expose to acids. Clean with warm soapy water and a soft cloth. Steam Cleaning Yes Ultrasonic Cleaning No

Agate (Blue Glitter Agate, Green Glitter Agate, Lavender Glitter Agate, Mystic Glitter Agate, Platin Glitter Agate, Rainbow Glitter Agate)

Treatment Surface treated, coated explanation Commonly used to produce unique colors Care Instructions Rinse in a bath of distilled soapy water, pat dry with a paper towel, and then briefly blow-dry. Steam Cleaning No Ultrasonic Cleaning No

Agate (Brown Moss Agate, Cherry blossom Agate, Grape Agate, Grey Agate, Javanese Moss Agate, Snake Agate, Tiger Agate)

Treatment None explanation N/A Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning Yes

Agate (Blue Lace Agate, Botswana Agate, Dendritic Agate, Druse Agate, Lagoon Lace Agate, Orange Botswana Agate, Sonora Dendrite Agate, Warrior Agate)

Treatment None explanation N/A Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning No

Agate (Black Glitter Agate, Bronze Glitter Agate, Cobalt Blue Glitter Agate, Cuprian Glitter Agate, Giolden Glitter Agate, Glitter Agate, Pearl Glitter Agate, Pink Glitter Agate, Silver Glitter Agate)

Treatment Dyeing explanation Spray paint, is generally used to create and/or improve the colour. Care Instructions Do not expose to thermal shocks. Soak briefly in mild soap and warm distilled water and rinse thoroughly with distilled water. Dry the surface with the cold setting of a hairdryer. Steam Cleaning No Ultrasonic Cleaning No

Agate (Dendrite Moss Agate, Lace Agate, Mexican Agate, Moss Agate, Prairie Agate, Red Moss Agate, Roter Botswana-Achat, Tree Agate, White Agate)

Treatment None explanation N/A Care Instructions None Steam Cleaning No Ultrasonic Cleaning No

Alexandrite (AAA Brasilian Alexandrite, AAA Russian Alexandrite, Alexandrite, Brazilian Alexandrite, Cat's Eye Alexandrite, Cat's Eye Brazilian Alexandrite, Russian Alexandrite, Tanzanian Alexandrite)

Treatment None explanation N/A Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning No

Amazonite (Amazonite)

Treatment Colourless oil and wax, paraffin or cured resin and/or impregnation with colourless plastic or cured resin explanation Colourless oil and wax are commonly used; impregnation with colourless plastic or cured resin is occasionally used to improve appearance and facilitate processing Care Instructions None Steam Cleaning No Ultrasonic Cleaning No

Amazonite (Amazonite Mosaic)

Treatment Compaction of amazonite with a bronze-copper alloy using resin, copper and heat. explanation To make the mosaic Care Instructions Keep away from heat and chemicals such as oils, perfumes and household cleaners. Do not swallow or ingest liquids containing amazonite. Steam Cleaning No Ultrasonic Cleaning No

Amazonite (Chocolate Amazonite)

Treatment None explanation N/A Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning Yes

Amber (Amber)

Treatment Heating and/or dyeing and/or reconstructing explanation Used to improve colour and appearance Care Instructions Gentle cleaning with a damp cloth Steam Cleaning No Ultrasonic Cleaning No

Amber (Baltic Amber)

Treatment Heating and/or dyeing. Only treatments approved by the International Amber Association are used. explanation Used to improve the colour Care Instructions Gentle cleaning with a damp cloth Steam Cleaning No Ultrasonic Cleaning No

Amber (Blue Colombian amber, Blue Colombian amber, Blue amber, Dominican Blue Amber, Dominican Green Amber, Dominican Red Amber, Green Colombian amber, Green amber, Red Colombian amber, Red amber)

Treatment Heating and dyeing. Copal is worked with heat and pressure to obtain this Amber rarity. explanation Used to improve colour and appearance Care Instructions Gentle cleaning with a damp cloth Steam Cleaning No Ultrasonic Cleaning No

Amblygonite (Amblygonite)

Treatment None explanation N/A Care Instructions With some stones, a temperature shock can lead to damage; do not expose to extreme temperature fluctuations. Steam Cleaning Yes Ultrasonic Cleaning No

Amethyst (Chevron Amethyst)

Treatment None explanation N/A Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning Yes

Amethyst (Druse Amethyst)

Treatment Oil-based spray coating explanation Cleans the stone surface, brings better shine and enhances the stone colour Care Instructions Do not use aggressive chemicals or cleaning liquids, salt water especially bleach or acids. Do not expose to strong sunlight. Steam Cleaning Yes Ultrasonic Cleaning No

Amethyst (Anahí-Amethyst, Arizona Amethyst)

Treatment Heating explanation Used for colour enhancement Care Instructions Some stones fade or return to their original colour when exposed to strong light; do not expose the gemstones unnecessarily to these conditions for a long time Steam Cleaning No Ultrasonic Cleaning No

Amethyst (Bolivian Amethyst, Zambian Amethyst)

Treatment None or heated explanation Used for colour improvement; about 50% of the material on the market is heated. Care Instructions Some stones fade or return to their original colour when exposed to strong light; do not expose the gemstones unnecessarily to these conditions for a long time Steam Cleaning No Ultrasonic Cleaning No

Amethyst (Green Amethyst, Rio Grande Green Amethyst)

Treatment Heating and/or irradiation explanation Generally used to emphasise and enhance colour Care Instructions None Steam Cleaning No Ultrasonic Cleaning No

Amethyst (Rose de France Amethyst, Santa Lucia Green Amethyst)

Treatment Heating explanation Used to improve colour and/or remove impurities/clouding Care Instructions Some stones fade or return to their original colour when exposed to strong light; do not expose the gemstones unnecessarily to these conditions for a long time Steam Cleaning No Ultrasonic Cleaning No

Amethyst (African Amethyst, Amethyst, Nigerian Amethyst)

Treatment None or heated explanation Occasionally used to improve colour and/or remove impurities/cloudiness Care Instructions Some stones fade or return to their original colour when exposed to strong light; do not expose the gemstones unnecessarily to these conditions for a long time Steam Cleaning No Ultrasonic Cleaning No

Amethyst (AAA Kalomo Amethyst, Brejinho Amethyst, Moroccan amethyst, Siberian Amethyst, Uruguayan Amethyst)

Treatment None explanation N/A Care Instructions Some stones fade when exposed to strong light; do not expose the gemstones unnecessarily long to these conditions. Steam Cleaning No Ultrasonic Cleaning No

Ametrine (Anahi Ametrine)

Treatment None explanation N/A Care Instructions Clean with lukewarm soapy water. Protect from heat. Steam Cleaning No Ultrasonic Cleaning No

Ametrine (Ametrine, Sunburst Ametrine)

Treatment Heating explanation Used for colour enhancement Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning No

Ammolite (Ammolite)

Treatment Sealing with epoxy resin explanation For stabilisation, a thin layer of epoxy resin is applied to the ammolite surface and ground along with it. Seals the surface and increases the robustness of the gemstone. Care Instructions Very fragile; treat with great care Steam Cleaning No Ultrasonic Cleaning No

Andalusite (Andalusite)

Treatment None explanation N/A Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning No

Andesine (AAA Andesine, AAA Red Andesine, Andesine, Green Andesine, Red Andesin)

Treatment None or heating and/or vapor deposition using copper explanation Occasionally used for colour enhancement Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning No

Angelite (Angelite, Green Angelite)

Treatment None explanation N/A Care Instructions May absorb moisture. Avoid scratches caused by harder substances. Do not expose to temperature changes. Do not bring into contact with water. Do not wear when doing sports, bathing or swimming. Clean with a soft, dry cloth. Steam Cleaning No Ultrasonic Cleaning No

Anglesite (Anglesite)

Treatment None explanation N/A Care Instructions Very fragile; treat with great care Steam Cleaning No Ultrasonic Cleaning No

Apatite (Fort Dauphin Apatite, Goias Neon Blue Apatite, Golden Apatite, Peach Apatite)

Treatment Heating explanation Used for colour enhancement Care Instructions none Steam Cleaning No Ultrasonic Cleaning No

Apatite (Apatite, Blue Apatite, Caribbean Blue Apatite, Indigo Apatite, Neon Blue Apatite, Royal blue Apatite)

Treatment None or heating, for cabochons the surface may be treated with wax and/or impregnated with colourless plastic or cured resin explanation Heating is used to improve the colour. Cabochons are made more resistant by impregnation/stabilisation and the porosity of the material is reduced. Care Instructions Avoidance of high temperatures and chemicals Steam Cleaning No Ultrasonic Cleaning No

Apatite (AAA Red Apatite, Canadian Apatite, Cat's Eye Apatite, Chrome Apatite, Fluoro Apatite, Green Apatite, Kunar Apatite, Lemon Apatite, Mint Apatit, Paraiba Apatite, Red Apatite, Russian Apatite, Xia Apatite, Yellow Apatite)

Treatment none explanation none Care Instructions none Steam Cleaning No Ultrasonic Cleaning No

Aquamarine (Aquamarine (Cabochon))

Treatment None or filling fissures with resin explanation for stabilization, prevents breakage and provides better shine Care Instructions None Steam Cleaning No Ultrasonic Cleaning No

Aquamarine (Ofiki Aquamarine)

Treatment Heating or filling fissures with resin explanation Heat to remove yellowish or greenish impurities; to achieve a clear, blue color tone, refill for stabilization, prevents breakage, and ensures better luster. Care Instructions Clean with warm soapy water and a soft cloth. Steam Cleaning No Ultrasonic Cleaning No

Aquamarine (Lundazi Aquamarine, Moss Aquamarine)

Treatment None explanation N/A Care Instructions Clean with warm soapy water and a soft cloth. Store dry and individually to avoid scratches. Avoid direct sunlight. Steam Cleaning No Ultrasonic Cleaning No

Aquamarine (Medina Aquamarine, Nigerian Aquamarine)

Treatment None explanation N/A Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning Yes

Aquamarine (AAA Aquamarine, AAA Brasilian Aquamarine, AAA Santa Maria Afrikana Aquamarine, AAA Santa Maria Aquamarine, Aquamarine, Bauchi Aquamarine, Boca Rica Aquamarine, Cat's Eye Aquamarine, Pedra Azul Aquamarine, Santa Maria Afrikana Aquamarine, Santa Maria Aquamarine, Santa Teresa Aquamarine, São Domingos Aquamarine, Tatu Aquamarine)

Treatment Heating explanation Generally used to remove yellowish or green impurities; to produce a clear blue hue. Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning No

Aragonite (Aragonite)

Treatment None explanation N/A Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning No

Aragonite (Orange Aragonite)

Treatment lacquered in engraving areas explanation For surface protection and polished appearance Care Instructions soft and delicate stone, can be easily scratched. Handle with care. Steam Cleaning No Ultrasonic Cleaning No

Astrophyllite (Astrophyllite)

Treatment None explanation N/A Care Instructions Do not expose to heat Steam Cleaning No Ultrasonic Cleaning No

Aventurine (Blue Aventurine)

Treatment Dyeing explanation Used for colour enhancement Care Instructions None Steam Cleaning No Ultrasonic Cleaning No

Aventurine (Peach Aventurine)

Treatment None explanation N/A Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning Yes

Aventurine (Anthracite Aventurine, Aventurine, Green Aventurine, Orange Aventurine, Red Aventurine)

Treatment None explanation N/A Care Instructions Aventurine can fade in prolonged exposure to sunlight. Do not expose to extreme temperatures. Clean with warm soapy water, a soft cloth or a soft toothbrush. Steam Cleaning No Ultrasonic Cleaning No

Axinite (Axinite)

Treatment None explanation N/D Care Instructions None Steam Cleaning No Ultrasonic Cleaning No

Azurite (Chrysokoll Azurite)

Treatment None explanation N/A Care Instructions Clean with warm soapy water and a soft cloth. Store separately from other pieces of jewellery to avoid scratching. Steam Cleaning No Ultrasonic Cleaning No

Azurite (K2-Azurit)

Treatment None explanation N/A Care Instructions None Steam Cleaning No Ultrasonic Cleaning No

Azurite (Mohave azurite)

Treatment Stabilisation and impregnation with copper particles or other metal particles and polymers explanation Asurite particles with copper particles and polymers are processed into this material to improve colour and create a more beautiful pattern. Care Instructions None Steam Cleaning No Ultrasonic Cleaning No

Azurite (Azur Malachite, Azurite Malachite)

Treatment Colourless oil and wax, paraffin or hardened resin and/or impregnation with colourless plastic or hardened resin explanation Colourless oil and wax are commonly used; impregnation with colourless plastic or cured resin is occasionally used to improve appearance and facilitate processing Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning No

B

Bamboo (Bamboo)

Treatment Dried and sealed with transparent enamel. explanation N/A Care Instructions Do not expose to liquids Steam Cleaning No Ultrasonic Cleaning No

Baryte (Baryte)

Treatment Filling fissures with resin explanation for stabilization, prevents breakage and provides better shine Care Instructions None Steam Cleaning No Ultrasonic Cleaning No

Benitoite (Benitoite)

Treatment None explanation N/A Care Instructions None Steam Cleaning No Ultrasonic Cleaning No

Beryl (Beryl)

Treatment None or heating and/or irradiation, in rare cases colouring explanation Used for colour enhancement Care Instructions Some stones fade or return to their original colour when exposed to strong light; do not expose the gemstones unnecessarily to these conditions for a long time Steam Cleaning Yes Ultrasonic Cleaning No

Beryl (Bixbite)

Treatment Colourless oil or resin explanation Frequently used to improve the colour Care Instructions None Steam Cleaning No Ultrasonic Cleaning No

Beryl (Emerald-coloured Beryl)

Treatment Fill cracks, cavities and fractures with hardened resin and dyeing explanation Generally used to create colour Care Instructions Fillings in, gaps, cracks and/or open fractures can scratch more easily than the parent stone and are more susceptible to damage by heat or solvents. Steam Cleaning No Ultrasonic Cleaning No

Beryl (Golden Madagascar Beryl)

Treatment Heating explanation Commonly used to create and enhance colour Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning Yes

Beryl (Green Beryl)

Treatment Dyeing explanation Frequently used to improve the colour Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning No

Beryl (Heliodor)

Treatment Irradiation explanation Used for colour enhancement Care Instructions Some stones fade or return to their original colour when exposed to strong light; do not expose the gemstones unnecessarily to these conditions for a long time Steam Cleaning Yes Ultrasonic Cleaning No

Beryl (Red Beryl)

Treatment none or oiled with colourless cedar oil explanation Used for colour enhancement Care Instructions None Steam Cleaning No Ultrasonic Cleaning No

Beryl (Amazon Beryl, Imperial Beryl, Unheated Pink Beryl)

Treatment None explanation N/A Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning No

Beryl (Béryl fantaisie, Golden Beryl, Yellow Beryl)

Treatment None or heated or irradiated explanation Used for colour enhancement Care Instructions Some stones fade or return to their original colour when exposed to strong light; do not expose the gemstones unnecessarily to these conditions for a long time Steam Cleaning Yes Ultrasonic Cleaning No

Bloodstone (Bloodstone)

Treatment None explanation N/A Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning Yes

C

Calcite (Alabaster Calcite)

Treatment None explanation N/A Care Instructions Sensitive, handle with care Steam Cleaning No Ultrasonic Cleaning No

Calcite (Mangano Calcite)

Treatment None explanation N/A Care Instructions Avoid scratches from harder substances. Some stones fade when exposed to strong light; do not expose the gemstones to these conditions for extended periods of time. Steam Cleaning No Ultrasonic Cleaning No

Calcite (Pink Calcite)

Treatment Figures are sealed with an acrylic clear coat. explanation To protect the surface Care Instructions Sensitive, handle with care Steam Cleaning No Ultrasonic Cleaning No

Calcite (Black Calcite, Orange Calcite)

Treatment Polishing and waxing. Generally used to improve the appearance. explanation Food-grade paraffin wax is used in polishing to seal the surface and improve the shiny appearance of the stone. Care Instructions Avoid scratches from harder substances. Some stones fade when exposed to strong light; do not expose the gemstones to these conditions for unnecessarily long periods. Avoid the use of bleaches and other aggressive chemicals. Steam Cleaning No Ultrasonic Cleaning No

Carnelian (Carnelian)

Treatment Dyeing and/or heating explanation Dyeing occasionally applied. Heating is generally common. Both methods are used to improve the colour. Care Instructions Some stones fade or return to their original colour when exposed to strong light; do not expose the gemstones unnecessarily to these conditions for a long time Steam Cleaning Yes Ultrasonic Cleaning No

Carnelian (Javanese Feather Carnelian)

Treatment None explanation N/A Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning Yes

Carnelian (Red Carnelian)

Treatment Dyeing explanation Used for colour enhancement Care Instructions keep away from direct fire and heat Steam Cleaning Yes Ultrasonic Cleaning No

Cerussite (Congo Cerussite, Namibian Cerussite)

Treatment Heating explanation N/A Care Instructions Relatively soft gemstone, handle with great care. Store individually to prevent scratches. Protect from heat. Avoid exposing to temperature shocks or fluctuations. Stone naturally contains lead. Wearing cerussite jewelry is safe. Steam Cleaning No Ultrasonic Cleaning No

Chalcedony (Lagoon Chalcedony)

Treatment Dyeing explanation Used for colour enhancement Care Instructions keep away from direct fire and heat Steam Cleaning No Ultrasonic Cleaning No

Chalcedony (Lavender Chalcedony)

Treatment Dyeing explanation Used for colour enhancement Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning No

Chalcedony (Peruan Aqua Chalcedony)

Treatment Dyeing explanation Used for colour enhancement Care Instructions keep away from direct fire and heat Steam Cleaning Yes Ultrasonic Cleaning Yes

Chalcedony (Ocean Chalcedony, White Chalcedony)

Treatment None explanation N/A Care Instructions Clean carefully with warm soapy water and soft cloth. Keep away from heat and chemicals such as oils, perfume and household cleaners. Steam Cleaning No Ultrasonic Cleaning No

Chalcedony (Aqua Chalcedony, Chalcedony, Green Chalcedony, Pink Chalcedony, Rasberry Chalcedony, Turkish Chalcedony)

Treatment None or dyeing explanation Dyeing is often used to improve the colour Care Instructions Some stones fade or return to their original colour when exposed to strong light; do not expose the gemstones unnecessarily to these conditions for a long time Steam Cleaning Yes Ultrasonic Cleaning Yes

Chalcedony (Blue Chalcedony, Green Chalcedony, Orange Chalcedony, Purple Chalcedony, Red Chalcedony, Yellow Chalcedony)

Treatment Dyeing explanation N/A Care Instructions Clean under running water or warm salt water. Do not use aggressive chemicals or cleaning liquids, especially bleach or acids, as they could damage the surface. Some stones will fade when exposed to strong light/heat; do not expose the gemstones to these conditions for an unnecessarily long time. Remove gemstone jewellery before exercising, gardening or housework. Store individually to avoid scratches. Steam Cleaning Yes Ultrasonic Cleaning No

Chalcedony (Blue Mohave Chalcedony, Chrome chalcedony, Fuchsia Mystic Quartz, Multicoloured Chalcedony, Pacific Chalcedony, Petrified Peach Chalcedony)

Treatment None explanation N/A Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning Yes

Chalcopyrite (Chalcopyrite)

Treatment None explanation N/A Care Instructions Clean only with cold water. Steam Cleaning No Ultrasonic Cleaning No

Charoite (Charoite)

Treatment None explanation N/A Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning Yes

Chrysoberyl (Brazilian Chrysoberyl, Cat's Eye Chrysoberyl, Chrysoberyl, Tunduru Chrysoberyl, Vanadium Chrysoberyl)

Treatment None explanation N/A Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning No

Chrysocolla (Chrysocolla)

Treatment Colourless oil and wax, paraffin or hardened resin and/or impregnation with colourless plastic or hardened resin explanation Colourless oil and wax are commonly used; impregnation with colourless plastic or cured resin is occasionally used to improve appearance and facilitate processing Care Instructions None Steam Cleaning No Ultrasonic Cleaning No

Chrysocolla (Chrysokoll Azurite, Chrysokoll Quartz)

Treatment None explanation N/A Care Instructions Clean with warm soapy water and a soft cloth. Store separately from other pieces of jewellery to avoid scratching. Steam Cleaning No Ultrasonic Cleaning No

Chrysoprase (Lemon Chrysoprase)

Treatment None explanation N/A Care Instructions Do not use harsh chemicals or cleaning liquids, especially bleach or acids. May fade with prolonged exposure to sunlight. Some specimens can regain their colour by storing them in a dark, humid box. Do not expose to extreme temperatures or hot water. Clean with warm soapy water, soft cloth or soft toothbrush. Steam Cleaning Yes Ultrasonic Cleaning Yes

Chrysoprase (Australischer Chrysopras, Chrysoprase, Imperial Chrysoprase)

Treatment None explanation N/A Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning Yes

Cinnabarite (Cinnabarite)

Treatment None explanation N/A Care Instructions None Steam Cleaning No Ultrasonic Cleaning No

Citrine (Palmeira Citrine)

Treatment None or heated explanation Used to improve the look and feel of the product. Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning Yes

Citrine (Bi Colour Citrine, Citrine)

Treatment Heating and/or irradiation explanation Commonly used to create and enhance colour Care Instructions Some stones fade or return to their original colour when exposed to strong light; do not expose the gemstones unnecessarily to these conditions for a long time Steam Cleaning No Ultrasonic Cleaning Yes

Citrine (Brandy Citrine, Canary Yellow Citrine)

Treatment Heating explanation Used for colour enhancement Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning Yes

Citrine (AAA Citrin, Imperial Citrine, Madeira Citrine, Mandarin Citrine)

Treatment Heating explanation Commonly used to create and enhance colour Care Instructions Some stones fade or return to their original colour when exposed to strong light; do not expose the gemstones unnecessarily to these conditions for a long time Steam Cleaning No Ultrasonic Cleaning Yes

Corundum (Ruby-coloured corundum, Sapphire-coloured corundum)

Treatment Heating and closing of cracks / cavities with the introduction of additives and dyeing explanation Generally used to create colour Care Instructions Fillings in, gaps, cracks and/or open fractures can scratch more easily than the parent stone and are more susceptible to damage by heat or solvents. Steam Cleaning No Ultrasonic Cleaning No

D

Danburite (Cat's Eye Danburite, Danburite, Mexican Pink Danburite)

Treatment None explanation N/A Care Instructions None Steam Cleaning No Ultrasonic Cleaning No

Demantoid (Ambanja-Demantoid, Demantoid, Madagascar Demantoid, Namibia-Demantoid)

Treatment None explanation N/A Care Instructions Do not expose to extreme temperatures, a temperature shock can cause damage. Steam Cleaning No Ultrasonic Cleaning No

Diamond (Black Diamond)

Treatment Heating and/or irradiation or Low Pressure High Temperature Treatment (LPHT) explanation Used for colour enhancement Care Instructions Black diamonds may not respond to diamond tester Steam Cleaning Yes Ultrasonic Cleaning Yes

Diamond (Salt-and-Pepper Diamond)

Treatment Dyeing explanation Used for colour enhancement Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning Yes

Diamond (Blue Diamond, Blue VS1 diamond, Canary F Diamond, Champagne Diamond, Chocolate Diamond, Cognac Diamond, Diamond, Emerald Green Diamond, Fancy Diamond, Forrest Green Diamond, Green Diamond, Natural Yellow SI Diamond, Orange Cognac Diamond, Orange diamond, Pink Champagne F Diamond, Pink Diamond, Pink VS1 Diamond, Pink VS2 Diamond, Red Cognac Diamond, Red Diamond, Royal Blue Diamond, SI Blue Diamond, SI Canary Yellow Diamond, SI Champagne Diamond, SI Cognac Diamond, SI Fancy Diamond, SI Green Diamon, SI Pink Diamond, SI Red Diamond, SI Yellow Diamond, SI1 Blue Diamond, SI1 Pink Diamond, Sky Blue Diamond, V1 Yellow Diamond, VS Blue Diamond, VS1 Green Diamond, VS1 Orange Diamond, VS1 Yellow Diamond, VS2 Blue Diamond, VS2 Green Diamond, VS2 Orange Diamond, VS2 Yellow Diamond, VVS2 Blue Diamond, Yellow Diamond, Yellow Gold Diamond, Yellow SI1 Diamond)

Treatment Usually heated and/or irradiated; extremely valuable if untreated explanation Used to enhance colour intensity or create unique colours. Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning Yes

Diamond (Argyle Champagne Diamond, Argyle Fancy Diamond, I1 (E) Diamond, I1 (F) Diamond, I1 (G) Diamond, I1 (H) Diamond, I2 (F) Diamond, IF (D) Diamond, IF (F) Diamond, IF (G) Diamond, IF (H) Diamond, Natural SI Argyle Diamond, SI Argyle Champagne Diamond, SI Argyle Fancy Diamond, SI Diamond, SI Rose de France Diamond, SI1 (D) Diamond, SI1 (E) Diamond, SI1 (F) Diamond, SI1 (G) Diamond, SI1 (H) Diamond, SI1 (I) Diamond, SI1 (J) Diamond, SI1 Argyle-Rose de France Diamond, SI1 Diamond, SI2 (E) Diamond, SI2 (F) Diamond, SI2 (G) Diamond, SI2 (H) Diamond, SI2 (I) Diamond, SI2 (J) Diamond, Silver coloured Diamond, Untreated Star Diamond, VS Argyle Champagne Diamond, VS Argyle Fancy Diamond, VS Diamond, VS1 (D) Diamond, VS1 (E) Diamond, VS1 (F) Diamond, VS1 (G) Diamond, VS1 (H) Diamond, VS1 (I) Diamond, VS1 (J) Diamond, VS1 Argyle-Rose de France Diamond, VS1 Diamond, VS1 Pink Diamond, VS2 (D) Diamond, VS2 (E) Diamond, VS2 (F) Diamond, VS2 (G) Canadian Diamond, VS2 (H) Diamond, VS2 (I) Diamond, VS2 (J) Diamond, VS2 Cognac Diamond, VS2 Diamond, VVS Argyle Champagne Diamond, VVS Argyle Fancy Diamond, VVS Diamond, VVS1 (D) Diamond, VVS1 (E) Diamond, VVS1 (F) Diamond, VVS1 (G) Diamond, VVS1 (H) Diamond, VVS1 (I) Diamond, VVS2 (D) Diamond, VVS2 (E) Diamond, VVS2 (F) Diamond, VVS2 (G) Diamond, VVS2 (H) Diamond, VVS2 (I) Diamond, VVS2 (J) Diamond)

Treatment None explanation N/A Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning Yes

Diaspore (Cat's Eye Colorchange Diaspore, Cat's Eye Diaspore, Colorchange Diaspore, Pink Diaspore)

Treatment None explanation N/A Care Instructions Do not expose to temperature shocks Steam Cleaning No Ultrasonic Cleaning No

Diopside (Black star diopside, Chrome Diopside, Diopside, Indian star diopside, Russian Diopside, Star Diopside)

Treatment None explanation N/A Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning No

Disthen (Disthen)

Treatment Crack filling before grinding explanation To protect sensitive stones during the grinding process. Over 99% of the sealant is removed during the fine grinding and polishing process. Care Instructions Clean with a soft cloth Steam Cleaning No Ultrasonic Cleaning No

Dolomit (Weißer Buffalo Dolomit)

Treatment None explanation N/A Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning Yes

Dumortierite (Dumortierite)

Treatment None explanation N/A Care Instructions None Steam Cleaning No Ultrasonic Cleaning No

E

Eilat stone (Eilat stone)

Treatment None explanation N/A Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning No

Emerald (Emerald)

Treatment Filling of cracks with colourless oils, plastics, waxes or resins and/or filling of cavities and fractures with cured resin; in rare cases, dyed explanation To improve the appearance and the inclusion pattern; colourless oils, plastics, waxes and resins are commonly used; filling cracks and cavities with synthetic resin is commonly used; colouring is used to improve the colour. Care Instructions Fillings can be damaged by heat or chemicals; do not expose to extreme temperature fluctuations Steam Cleaning No Ultrasonic Cleaning No

Emerald (Tanzanian Emerald)

Treatment None explanation N/A Care Instructions None Steam Cleaning No Ultrasonic Cleaning No

Emerald (AAA Brazilian Emerald, AAA Zambian Emerald, Brasilian Emerald, Colombian Emerald, Fernao Dias Emerald, Nova Era Emerald, Zambian Emerald)

Treatment Filling of cracks with colourless oils and/or plastics, waxes or resins and/or filling of cavities and cracks with cured resin explanation To improve appearance and inclusion pattern; colourless oils, plastics, waxes and resins are commonly used; filling cracks and cavities with synthetic resin is commonly used Care Instructions Fillings can be damaged by heat or chemicals; do not expose to extreme temperature fluctuations Steam Cleaning No Ultrasonic Cleaning No

Emerald (AAA Colombian Emerald, AAA Russian Emerald, Bahia Emerald, Kagem-Smaragd, Sao Francisco Emerald, Socoto Emerald, Transvaal Emerald, Äthiopischer Smaragd)

Treatment Filling cracks with colourless oils explanation The colourless oils are used to improve the appearance and the inclusion pattern. Care Instructions Fillings can be damaged by heat or chemicals; do not expose to extreme temperature fluctuations Steam Cleaning No Ultrasonic Cleaning No

Euclase (Brasilian Euclase, Euclase)

Treatment None explanation N/A Care Instructions None Steam Cleaning No Ultrasonic Cleaning No

F

Fluorite (Blue Fluorite, Colour Change Fluorite, Green Fluorite, Mint Fluorite, Purple Fluorite, Purpur-Fluorit, Red Fluorite, Yellow Fluorite)

Treatment None or irradiated explanation Used to enhance or evoke the desired colour Care Instructions Protect from heat and dry environment! Do not expose to extreme temperatures, a temperature shock can cause damage; some stones will fade or return to their original colour when exposed to strong light; do not expose the gemstones to these conditions unnecessarily long! Steam Cleaning No Ultrasonic Cleaning No

Fluorite (Belgian Carribean Teal Fluorite, Bi Colour Fluorite, Blue Fluorite, Cumbrian Fluorite, Esperanza Fluorite, Mexian pink fluorite, Namibian Mint Fluorite, Pink Fluorite, Spanish Fluorite, White Fluorite, Yellow Fluorite)

Treatment None explanation N/A Care Instructions Protect from heat and dry environment! Do not expose to extreme temperatures, a temperature shock can cause damage; some stones will fade or return to their original colour when exposed to strong light; do not expose the gemstones to these conditions unnecessarily long! Steam Cleaning No Ultrasonic Cleaning No

Fossil (Bog oak)

Treatment None explanation N/A Care Instructions Handle with care. Avoid contact with cosmetics such as perfume, hairspray, creams and household cleaners. Do not expose to high temperatures. Clean with a soft, dry cloth without additives. Reacts sensitively to water. If it gets wet, dry slowly at room temperature. Steam Cleaning No Ultrasonic Cleaning No

Fossil (Goniatite)

Treatment Polishing and waxing. explanation Used to improve the look and feel of the product. Care Instructions Do not use aggressive cleaning agents. Do not bring into contact with acids. Do not degrease. Steam Cleaning No Ultrasonic Cleaning No

Fossil (Mammut Elfenbein)

Treatment None explanation N/A Care Instructions Handle with care. Avoid contact with cosmetics such as perfume, hairspray, creams and household cleaners. Do not expose to high temperatures. Clean with a soft, dry cloth. Steam Cleaning No Ultrasonic Cleaning No

Fossil (Zwenkau druse wood)

Treatment None explanation N/A Care Instructions natural surface is sensitive, treat with care to avoid fractures Steam Cleaning No Ultrasonic Cleaning No

Fossil (Bufonite Fossil, Petrified Jambi palm wood, Petrified Red Soft Coral, Petrified coral, Petrified palm wood, Petrified wood)

Treatment None explanation N/A Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning Yes

Fuchsit (Ruby fuchsite)

Treatment Surface treatment with wax explanation closes small pores in the stone Care Instructions Do not remove wax, as this can cause the stones to lose their shine and polish. Steam Cleaning No Ultrasonic Cleaning No

G

Gabbro (Merlinit-Gabbro)

Treatment None explanation N/A Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning Yes

Garnet (AAA Mandarin Garnet, AAA Mozambique Garnet, AAA Umbalite, Blue Colour Change Garnet, Brasilian Rhodonite, Cinnamon Garnet, Colour Change Garnet, Cuamba Garnet, Demantoid, Farbwechsel-Malaya-Granat, Four Ray Star Garnet, Garnet, Hessonite, Hessonite Garnet, Imperial Garnet, Imperial Minas Garnet, Indian Garnet, Kamtonga Colour Change Garnet, Lindi Granat, Madagascar Colour Change Garnet, Magenta Garnet, Malawi Garnet, Malaya Garnet, Mandarin Garnet, Merelani Garnet, Merelani Mint Garnet, Mint Garnet, Mint Tsavorite, Mozambique Garnet, Orissa Garnet, Pyrope, Red Garnet, Rhodolite, Rhodonite, Rift Valley Rhodolite, Royal Purlpe Garnet, Six Ray Star Garnet, Star Garnet, Tangerin Garnet, Tanzanian Colour Change Garnet, Tocantin Garnet, Topazolite, Tsavorite, Umbalite, Urumba Garnet)

Treatment None explanation N/A Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning Yes

Gem Silica (Gem Silica)

Treatment None explanation N/A Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning Yes

Goshenite (Cat's Eye Goshenite, Goshenite)

Treatment None explanation N/A Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning No

Grandidierite (Grandidierite, Grandidierite Cat’s Eye)

Treatment None explanation N/A Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning No

H

Hauyne (Hauyne)

Treatment None explanation N/A Care Instructions Softly clean with mild soap, soft toothbrush and lukewarm water. After cleaning dry with a soft cloth or chamois leather. Steam Cleaning No Ultrasonic Cleaning No

Hematite (Hematite)

Treatment none or coating explanation Used to improve colour and surface texture Care Instructions Coated or surface-treated gemstones cannot be resharpened and polished. Steam Cleaning Yes Ultrasonic Cleaning Yes

Hematite (Bronze Hematite, Cuprian Hematite, Multicoloured haematite, Titan Haematite)

Treatment Surface treated, coated explanation Thin-film finishing by vapour deposition of nanoparticles consisting of various precious and semi-precious metals (including gold), oxides and nitrides, which are durable and long-lasting if care instructions are followed. Environmentally friendly process without harmful chemicals. Care Instructions Do not use any aggressive chemicals or cleaning fluids, especially bleach or acids. Clean with warm soapy water and a soft cloth. Remove jewellery during sport and housework. Steam Cleaning No Ultrasonic Cleaning No

Hematite (Chocolate Hematite, Golden Hematite, Green Hematite, Green Mystic Hematite, Mocha Hematite, Mystic Hematite, Pink Mystic Hematite, Purlpe Hematite, Purple Mystic Hematite, Red Hematite, Rose Hematite)

Treatment Coating explanation Generally used to improve/strengthen the colour or to create unique colours Care Instructions Do not use aggressive chemicals or cleaning fluids, especially bleach or acids. Clean with warm soapy water and a soft cloth. Remove jewellery during sports and housework. To store, wrap in a soft cloth or place in a fabric-lined jewellery box. Steam Cleaning No Ultrasonic Cleaning No

Hiddenit (Hiddenit)

Treatment Irradiation explanation Rarely used to create the colour or its uniformity. Care Instructions Some stones fade or return to their original colour when exposed to strong light; do not expose the gemstones unnecessarily to these conditions for a long time Steam Cleaning Yes Ultrasonic Cleaning No

Howlite (Blue Howlite, Howlite)

Treatment White is untreated, other colours are coloured explanation To evoke bright colours, often in blue or turquoise, to imitate lapis lasuli or turquoise Care Instructions None Steam Cleaning No Ultrasonic Cleaning No

I

Idocrase (Idocrase)

Treatment None explanation N/A Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning Yes

Igneous Rock (Black Lava Pearl")

Treatment None explanation N/A Care Instructions Do not bring open-pored lava beads into contact with liquids, chemicals, sea or pool water. Store individually to protect against scratches. Steam Cleaning No Ultrasonic Cleaning No

Igneous Rock (Golden Lava Pearl, Royal Blue Lava Pearl, White Lava Pearl)

Treatment Dyeing explanation Generally used to evoke and/or enhance colour. Care Instructions Do not bring open-pored lava beads into contact with liquids, chemicals, sea or pool water. Store individually to protect against scratches. Steam Cleaning No Ultrasonic Cleaning No

Igneous Rock (Blue Lava Pearl, Blue Mystic Lava Pearl, Chocolate Lava Pearl, Lava Pearl, Mystic Lava Pearl, Pink Lava Pearl, Purple Lava Pearl, Silver coloured Lava Pearl)

Treatment surface-treated, coated explanation Electroplating, durable and long-lasting if care instructions are followed. Care Instructions Do not bring open-pored lava beads into contact with liquids, chemicals, sea or pool water. Store individually to protect against scratches. Steam Cleaning No Ultrasonic Cleaning No

Indicolite (Brasilian Indicolite)

Treatment None explanation N/A Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning No

Indicolite (Cat's Eye Indicolite)

Treatment None explanation N/A Care Instructions Do not use harsh chemicals or cleaning liquids, do not expose to extreme temperatures. Protect from knocks or scratches, this can damage the surface. Steam Cleaning No Ultrasonic Cleaning No

Indicolite (AAA-Mutuca-Indigolite, Bi Colour Mutuca Indicolite, Cat's Eye Mutuca Indicolite, Indicolite, Mutuca Indicolite)

Treatment None or heated explanation N/A Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning No

Iolite (Ceylon Iolite, Iolite, Madagascar Iolite, Orissa Iolite)

Treatment None explanation N/A Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning Yes

J

Jade (Turkish Jade)

Treatment None explanation N/A Care Instructions Softly clean with mild soap, soft toothbrush and lukewarm water. After cleaning dry with a soft cloth or chamois leather. Steam Cleaning Yes Ultrasonic Cleaning No

Jade (African Jade, Yellow Jade)

Treatment None explanation N/A Care Instructions Do not use aggressive chemicals or cleaning liquids. Clean carefully with warm soapy water and soft cloth to avoid scratching the surface of the stone. Do not soak in water. Steam Cleaning No Ultrasonic Cleaning No

Jade (Blue Jade, Pink Jade)

Treatment Dyeing explanation Generally used to emphasise and improve colour Care Instructions Keep away from heat and chemicals such as oils, perfume and household cleaners. Steam Cleaning No Ultrasonic Cleaning No

Jade (Australian Jade, Azurite, Canadian Jade, Cat's Eye Nephrite, Jade, Jadeite, Nephrite)

Treatment None or mostly dyeing or impregnating with colourless oil, wax or resin and or heating; Jadeite is also impregnated with plastics or polymers, followed by an acid treatment. explanation Often used to improve or create the colour or to create it in uniformity. Care Instructions None Steam Cleaning No Ultrasonic Cleaning No

Jadeite (Blue Jadeite, Lavender Jadeite, Red Jadeite)

Treatment Dyeing explanation Used to improve the colour Care Instructions None Steam Cleaning No Ultrasonic Cleaning Yes

Jadeite (Black Jadeite, Golden Jadeite, Green Jadeite, Honey Jadeite, Jadeite, Majestic Jadeite, Noble Green Jadeite, Royal Green Jadeite, White Jadeite)

Treatment None explanation N/A Care Instructions Do not bring into contact with acids, do not expose to extreme heat. Steam Cleaning Yes Ultrasonic Cleaning Yes

Jasper (Impression Jasper)

Treatment Natural colour, stabilised explanation Stabilising reduces porosity and improves the surface. Care Instructions None Steam Cleaning No Ultrasonic Cleaning No

Jasper (Pink Zebra Jasper, Zebra Jasper)

Treatment None explanation N/A Care Instructions Clean with warm soapy water and a soft cloth. After cleaning dry with a soft cloth. Do not expose to high temperatures for long periods of time, this can lead to colour changes. Steam Cleaning No Ultrasonic Cleaning Yes

Jasper (Australian Jasper, Black Net Jasper, Rainbow Jasper, Red Snake Skin Jasper, Red Zebra Jasper, Silver Leaf Jasper, Tree Jasper)

Treatment None explanation N/A Care Instructions Clean carefully with warm soapy water and soft cloth or soft toothbrush. Steam Cleaning No Ultrasonic Cleaning No

Jasper (Breccia Jasper, Dalmatian Jasper, Dragon Jasper, Jasper, Ocelot Jasper, Spider Web Jasper, Sunset Jasper, White Jasper)

Treatment None explanation N/A Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning Yes

Jasper (Bumble Bee Jasper, Leopard Jasper, Noreena Jasper, Ocean Jasper, Peanut Jasper, Picture Jasper, Picture Jasper, Pilbara Jasper, Red Jasper, Sonora Dendrite Jasper, Sunflower Jasper, Turtella Jasper)

Treatment Dyeing explanation Is used to create the colour; is often used to imitate other coloured stones Care Instructions Some stones fade or return to their original colour when exposed to strong light; do not expose the gemstones unnecessarily to these conditions for a long time Steam Cleaning No Ultrasonic Cleaning No

K

Kunzite (AAA Brazilian Kunzite, California Kunzite, Yellow Kunzite)

Treatment None explanation N/A Care Instructions Some stones fade when exposed to strong light; do not expose the gemstones unnecessarily long to these conditions. Steam Cleaning No Ultrasonic Cleaning No

Kunzite (AAA Kunzite, AAA Urucum Kunzite, Brasilian Kunzite, Kunzite, Patroke Kunzite, White Kunzite)

Treatment none or heating and/or irradiation, for cabochons none or saturation with plastic or polymers explanation Often used to improve the colour and/or produce a darker colour, saturation is applied to rough gemstones to make them easier to work with and to improve the surface texture Care Instructions Some stones fade or return to their original colour when exposed to strong light; do not expose the gemstones unnecessarily to these conditions for a long time Steam Cleaning No Ultrasonic Cleaning No

Kyanite (Orange Tanzanian Kyanite)

Treatment None explanation N/A Care Instructions Avoid the use of bleach and other aggressive chemicals. The surface gloss is sometimes enhanced by oil. This can affect the care of gemstones. Use soft cloths. Then dab repeatedly until dry. Store in a cloth bag. Steam Cleaning No Ultrasonic Cleaning No

Kyanite (Green Kyanite, Kyanite, Mint Kyanite, Nepalese kyanite, Peacock Kyanite, Petrol Cyanite, Tibetan Kyanite)

Treatment None explanation N/A Care Instructions None Steam Cleaning No Ultrasonic Cleaning No

L

Labradorite (Labradorite)

Treatment Surface treatment with colourless wax explanation Occasionally used to improve appearance Care Instructions None Steam Cleaning No Ultrasonic Cleaning No

Labradorite (Golden Labradorite, White Labradorite)

Treatment None explanation N/A Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning Yes

Labradorite (Blue Maniry Labradorite, Cuprian Maniry Labradorite, Golden Maniry Labradorite, Green Maniry Labradorite, Maniry Labradorite, Purple Maniry Labradorite)

Treatment None explanation N/A Care Instructions Clean under running water. Do not use aggressive chemicals or cleaning liquids, especially bleach or acids. Steam Cleaning No Ultrasonic Cleaning No

Lapis Lazuli (Lapis Lazuli)

Treatment Surface treatment with colourless wax and/or dyeing explanation Generally used to produce colour and/or improve its uniformity. Care Instructions None Steam Cleaning No Ultrasonic Cleaning No

Larimar (Cuprian Larimar)

Treatment Sealing cracks with resin. explanation to improve the grinding properties Care Instructions None Steam Cleaning No Ultrasonic Cleaning No

Larimar (Larimar)

Treatment None explanation N/A Care Instructions Clean gently with a jewellery cleaning cloth that is also suitable for pearls. Steam Cleaning No Ultrasonic Cleaning No

Larvikite (Larvikite)

Treatment None explanation N/A Care Instructions Clean with warm soapy water and a soft cloth. Steam Cleaning No Ultrasonic Cleaning No

Lepidolite (Lepidolite)

Treatment None explanation N/A Care Instructions Clean with warm soapy water and a soft cloth. Steam Cleaning No Ultrasonic Cleaning No

Lizardite (Lizardite)

Treatment Growing of the surface. Generally used to improve the appearance. explanation Waxing protects and seals the polished surface of the stone. Care Instructions Clean with a soft cloth Steam Cleaning No Ultrasonic Cleaning No

M

Magnesite (Blue Magnesite)

Treatment Dyeing explanation Used to obtain the colour or uniformity of the colour. Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning No

Magnesite (Blue Magnesite, Lemon Magnesite, Magnesite, Pristine Magnesite, Wild Horse Magnesite)

Treatment None explanation N/A Care Instructions None Steam Cleaning No Ultrasonic Cleaning No

Malachite (Malachite)

Treatment Surface treatment with colourless wax and/or impregnation with colourless plastic or cured resin explanation Surface treatment with colourless wax and/or sheathing with colourless wax is occasionally used to improve the colour. Care Instructions None Steam Cleaning No Ultrasonic Cleaning No

Marble (Picture Marble)

Treatment Polishing and waxing explanation to improve the appearance Care Instructions Sensitive, handle with care Steam Cleaning No Ultrasonic Cleaning Yes

Marble (White Marble)

Treatment None explanation N/A Care Instructions Sensitive, handle with care Steam Cleaning No Ultrasonic Cleaning Yes

Marcasite (Marcasite)

Treatment None explanation N/A Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning Yes

Mariposite (Mariposite)

Treatment None explanation N/A Care Instructions None Steam Cleaning No Ultrasonic Cleaning No

Meteorite (Iron Meteorite)

Treatment None explanation N/A Care Instructions None Steam Cleaning No Ultrasonic Cleaning No

Meteorite (Muonionalusta Meteorit, Vredefort Meteorite)

Treatment Coating explanation Coating to protect against rusting and oxidation Care Instructions Coated or surface-treated gemstones cannot be resharpened and polished. Steam Cleaning No Ultrasonic Cleaning No

Mica (Golden Mica)

Treatment None explanation N/A Care Instructions Keep away from heat and chemicals such as oils, perfume and household cleaners. Steam Cleaning No Ultrasonic Cleaning No

Moldavite (Moldavite)

Treatment None explanation N/A Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning Yes

Mookite (Mookite)

Treatment Heating explanation Cutting the gemstone after heating Care Instructions None Steam Cleaning No Ultrasonic Cleaning No

Moonstone (Blue Mystic Moonstone, Mystic Moonstone, Peachy Mystic Moonstone)

Treatment Coating and dyeing explanation The coating is produced by placing in a rhodium bath and it produces a special surface shine. For example, the blue version is dyed to create the colour. Care Instructions Coated or surface-treated gemstones cannot be resharpened and polished. Steam Cleaning No Ultrasonic Cleaning No

Moonstone (AAA Moonstone, AAA Rainbow Moonstone, Bihar Rainbow Moonstone, Blue Moonstone, Cat's Eye Ceylon Moonstone, Cat's Eye Chocolate Moonstone, Cat's Eye White Moonstone, Cat's eye Moonstone, Ceylon Moonstone, Ceylon-Regenbogen-Mondstein, Chocolate Moonstone, Green Moonstone, Kangeyam Moonstone, Mocha Moonstone, Moonstone, Peach Moonstone, Rainbow Moonstone, Silver moonstone, Tanzanian Rainbow Moonstone, White Moonstone)

Treatment None explanation N/A Care Instructions Do not use aggressive chemicals or cleaning liquids, especially bleach or acids. Clean with warm soapy water and soft cloth. Rinse well with warm water to remove any soap film and residue as this may dull the shine of the gemstone. Steam Cleaning No Ultrasonic Cleaning No

Morganite (AAA Nigerian Morganite)

Treatment None or irradiated explanation Often used to remove unwanted yellow tones Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning No

Morganite (AAA Brasisilan Morganite, AAA Madagascan Morganite, AAA Morganite, Brasilian Morganite, Peach Morganite)

Treatment Heating explanation Often used to remove unwanted yellow tones Care Instructions None Steam Cleaning No Ultrasonic Cleaning No

Morganite (AAA-Peach Morganite, Imperial Morganite, Madagascan Morganite, Marropino Morganite, Morganite, Nigerian Morganite)

Treatment Heating and/or irradiation explanation Often used to remove unwanted yellow tones Care Instructions None Steam Cleaning No Ultrasonic Cleaning No

Mother of Pearl (Pinctada Mother of Pearl)

Treatment None explanation N/A Care Instructions Sensitive, handle with care Steam Cleaning No Ultrasonic Cleaning Yes

Mother of Pearl (Mother of Pearl Mosaic, Pinctada Mother of Pearl Mosaic)

Treatment Hand-set mosaic with gel filling explanation To make the mosaic Care Instructions Keep away from heat and chemicals such as oils, perfume and household cleaners. Steam Cleaning No Ultrasonic Cleaning No

Muscovite (Muscovite)

Treatment Filling fissures explanation N/A Care Instructions Cleavage planes of the mica are particularly sensitive, avoid impacts Steam Cleaning No Ultrasonic Cleaning No

O

Obsidian (Fireworks Obsidian)

Treatment Stabilizing with epoxy resin and acetone explanation Generally applied to create color and patterns. Improves properties during the grinding process. Care Instructions None Steam Cleaning No Ultrasonic Cleaning No

Obsidian (Mahogany Obsidian, Mount Saint Helens Obsidian, Obsidian, Red Snowflake Obsidian, Silver Obsidian, Silver Sheen Obsidian, Snowflake Obsidian)

Treatment None explanation N/A Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning No

Onyx (Blue Onyx)

Treatment Heating explanation Generally used to evoke and/or enhance colour. Care Instructions Clean with a soft/dry or slightly damp cloth or soft brush. However, do not wet the stone or immerse it in water as liquids can be absorbed. Steam Cleaning Yes Ultrasonic Cleaning Yes

Onyx (White Onyx)

Treatment None explanation N/A Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning Yes

Onyx (Black Onyx, Onyx, Stripe Onyx)

Treatment Dyeing explanation Used to obtain the colour or uniformity of the colour. Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning Yes

Onyx (Green Onyx, Pink Onyx, Red Onyx)

Treatment Dyeing explanation Generally used to improve/strengthen the colour or to create unique colours. Care Instructions Clean with a dry or slightly damp cloth or soft brush to remove dust. Do not wet stone and place in a water bath, stone can absorb water. Steam Cleaning No Ultrasonic Cleaning No

Opal (Angel skin Opal)

Treatment Polish explanation N/A Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning Yes

Opal (Blue Opal)

Treatment Mostly none, occasionally heating explanation Used for colour enhancement Care Instructions Protect from heat, dry and wet environment! Do not expose the gemstones to extreme temperatures, a temperature shock can cause damage; some stones fade when exposed to strong light. Some stones may lose their color play if exposed to too much moisture. Do not expose the gemstones to these conditions unnecessarily long! Steam Cleaning No Ultrasonic Cleaning No

Opal (Fluorite Opal)

Treatment None explanation N/A Care Instructions Clean with warm soapy water and a soft cloth. Steam Cleaning Yes Ultrasonic Cleaning No

Opal (Machu Picchu Opal)

Treatment Cavities are filled with unhardened, colourless substances explanation Used to improve the look and feel of the product. Care Instructions Protect from heat, dry and wet environment! Do not expose the gemstones to extreme temperatures, a temperature shock can cause damage; some stones fade when exposed to strong light. Some stones may lose their color play if exposed to too much moisture. Do not expose the gemstones to these conditions unnecessarily long! Steam Cleaning No Ultrasonic Cleaning No

Opal (Opalholz)

Treatment Sealing with epoxy resin explanation For sealing the surface Care Instructions Clean with water and mild soap Steam Cleaning No Ultrasonic Cleaning No

Opal (Pink Andes Opal)

Treatment None explanation N/A Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning Yes

Opal (Pink Opal)

Treatment Heating explanation Used for colour enhancement Care Instructions Protect from heat, dry and wet environment! Do not expose the gemstones to extreme temperatures, a temperature shock can cause damage; some stones fade when exposed to strong light. Some stones may lose their color play if exposed to too much moisture. Do not expose the gemstones to these conditions unnecessarily long! Steam Cleaning No Ultrasonic Cleaning No

Opal (Pink Opal Mosaic)

Treatment Compression with calcite and bronze-copper alloy using resin, copper and heat. explanation Creating the mosaic Care Instructions Keep away from heat and chemicals such as oils, perfume and household cleaners. Do not swallow. Steam Cleaning No Ultrasonic Cleaning No

Opal (Andes Opal, Blue Atacama Opal, Honduras opal)

Treatment Filling fissures explanation Sealing of the stone for polishing and to avoid fractures at natural fissure lines Care Instructions Handle with care. Keep away from solvents and household cleaners. Steam Cleaning No Ultrasonic Cleaning No

Opal (Brazilian Green Opal, Honey Opal, Mintabie Jelly Opal, Purple Opal)

Treatment None explanation N/A Care Instructions Keep away from water, liquids and chemicals. Do not expose to extreme temperatures, thermal shock can cause damage. Steam Cleaning No Ultrasonic Cleaning No

Opal (Lavender Opal, Matrix Opal, Mezezo Opal, Orange Opal)

Treatment With organic substances heating and dyeing, also known as "Sugar Treatment". explanation Used to improve the look and feel of the product. Care Instructions Protect from heat, dry and wet environment! Do not expose the gemstones to extreme temperatures, a temperature shock can cause damage; some stones fade when exposed to strong light. Some stones may lose their color play if exposed to too much moisture. Do not expose the gemstones to these conditions unnecessarily long! Steam Cleaning No Ultrasonic Cleaning No

Opal (Carribean Blue Opal, Ethiopian Pink Opal, Ethopian Blue Opal, Ethopian Green Opal, Ethopian Red Opal, Ethopian Yellow Opal, Sky Blue Opal)

Treatment Dyeing explanation Generally used to evoke and/or enhance colour. Care Instructions Protect from heat, dry environments and moisture. Do not expose to extreme temperatures, thermal shock can cause damage; do not expose to strong light. Some stones can lose their colour if they are exposed to too much moisture. Do not expose the gemstones to these conditions for an unnecessarily long time. Steam Cleaning No Ultrasonic Cleaning No

Opal (Australian Pink Opal, Blue Ethiopian Matrix Opal, Crystal Opal, Green Ethiopian Matrix Opal, Karoit Nut Opal, Mexican Hyalite Opal, Red Ethiopian Matrix Opal, Yowah Nut Opal)

Treatment None explanation N/A Care Instructions None Steam Cleaning No Ultrasonic Cleaning No

Opal (AAA Mexican Fire Opal, AAA Welo Opal, Australian Opal, Blue Fire Opal, Boulder Opal, Buriti Fire Opal, Cat's Eye Opal, Ice Opal, Imperial Jalisco Fire Opal, Indian Opal, Indonesian Opal, Javanese Opal, Kalimaya Opal, Lambina Fire Opal, Leopard Opal, Lightning Ridge Black Crystal Opal, Lightning Ridge Black Opal, Lightning Ridge Opal, Lightning Ridge Semi Black Opal, Lightning Ridge-Crystal-Opal, Los Labos Opal, Los Lobos Opal, Mali-Opal, Mexican Fire Opal, Opal, Paraiba Opal, Queretaro Cherry Fire Opal, Salamanca Fire Opal, Welo Opal, White Opal, Yellow Opal)

Treatment None explanation In some cases, the inside of the frame is darkened to give a better colour result. However, since nothing is changed on the gemstone, this is not a treatment. Care Instructions Protect from heat, dry and wet environment! Do not expose the gemstones to extreme temperatures, a temperature shock can cause damage; some stones fade when exposed to strong light. Some stones may lose their color play if exposed to too much moisture. Do not expose the gemstones to these conditions unnecessarily long! Steam Cleaning No Ultrasonic Cleaning No

Orthoceras (Orthoceras)

Treatment Polishing and waxing. Generally used to improve the appearance. explanation Food-grade paraffin wax is used in polishing to seal the surface and improve the shiny appearance of the stone. Care Instructions Avoid scratches from harder substances. Some stones fade when exposed to strong light; do not expose the gemstones to these conditions for unnecessarily long periods. Avoid the use of bleaches and other aggressive chemicals. Steam Cleaning No Ultrasonic Cleaning No

Orthoclase (Orthoclase)

Treatment None explanation N/A Care Instructions None Steam Cleaning No Ultrasonic Cleaning No

P

Pearl (Mystic Freshwater Cultured Pearl)

Treatment Dyeing explanation Generally used to emphasise and improve colour Care Instructions After each wear, wipe beads with a soft cloth to prevent the build-up of oils or other substances. If necessary, clean gently with a damp cloth. Steam Cleaning No Ultrasonic Cleaning No

Pearl (Mystic Keshi Pearl)

Treatment bleaching explanation Generally used to emphasise and improve colour Care Instructions After each wear, wipe beads with a soft cloth to prevent the build-up of oils or other substances. If necessary, clean gently with a damp cloth. Steam Cleaning No Ultrasonic Cleaning No

Pearl (Black Mabe Pearl, Mabe Pearl)

Treatment May also be bleached, dyed, chemically treated or irradiated. These Pearls are also classified as composite gemstones. explanation Used for production. Other optional treatments are occasionally used to improve and/or change the colour and/or create uniformity. Care Instructions After each wear, wipe beads with a soft cloth to prevent the build-up of oils or other substances. If necessary, clean gently with a damp cloth. Steam Cleaning No Ultrasonic Cleaning No

Pearl (Black Freshwater Cultured Keshi Pearl, Golden Kabira South Sea Pearl, Keshi Pearl, Rainbow Freshwater Cultured Pearl)

Treatment None explanation N/A Care Instructions After each wear, wipe beads with a soft cloth to prevent the build-up of oils or other substances. If necessary, clean gently with a damp cloth. Steam Cleaning No Ultrasonic Cleaning No

Pearl (Akoya Pearl, Freshwater pearl, Freshwater pearl, Golden South Sea Pearl, Imperial Pearl, Kasumigaura Baroque Pearl, Kasumigaura Pearl, Ming Pearl, Silver South Sea Pearl, South Sea Pearl, Tahitian Pearl, White South Sea Pearl)

Treatment Bleaching, dyeing, chemical treatment or irradiation. Most pearls are cultured pearls. explanation Used to change, improve and/or uniform the colour. Care Instructions After each wear, wipe beads with a soft cloth to prevent the build-up of oils or other substances. If necessary, clean gently with a damp cloth. Steam Cleaning No Ultrasonic Cleaning No

Peridot (Arizona Peridot)

Treatment Heating, filling cracks and cavities with colourless oils, waxes and resins explanation Rarely used to improve appearance Care Instructions With some stones, a temperature shock can lead to damage; do not expose to extreme temperature fluctuations. Steam Cleaning No Ultrasonic Cleaning No

Peridot (Burmese Peridot, Jilin peridot, Kashmir Peridot, Manchurian Peridot)

Treatment None explanation N/A Care Instructions With some stones, a temperature shock can lead to damage; do not expose to extreme temperature fluctuations. Do not bring into contact with acids. Steam Cleaning No Ultrasonic Cleaning No

Petalite (Petalite)

Treatment None explanation N/A Care Instructions None Steam Cleaning No Ultrasonic Cleaning No

Phosphosiderite (Phosphosiderite)

Treatment None explanation N/A Care Instructions None Steam Cleaning No Ultrasonic Cleaning No

Pietersite (Golden Pietersite, Pietersite)

Treatment None explanation N/A Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning Yes

Prehnite (Prehnite)

Treatment None explanation N/A Care Instructions None Steam Cleaning No Ultrasonic Cleaning No

Psilomelane (Psilomelane)

Treatment None explanation N/A Care Instructions None Steam Cleaning No Ultrasonic Cleaning No

Pyrite (Pyrite)

Treatment None explanation N/A Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning Yes

Pyrite Slate (Pyrite Slate)

Treatment Surface treatment with wax, filling of fissures explanation Sealing of micro-fissures between pyrite and slate to protect pyrite from tarnishing Care Instructions Clean with soft cloth. Keep away from water, liquids and chemicals. Steam Cleaning No Ultrasonic Cleaning No

Pyroxenit (Garnet pyroxenite)

Treatment Surface treatment with wax, filling of fissures explanation Sealing of micro-fissures Care Instructions None Steam Cleaning No Ultrasonic Cleaning Yes

Q

Quartz (Blue Crushed Ice Quartz)

Treatment Heating and dyeing explanation Used for colour enhancement Care Instructions None Steam Cleaning No Ultrasonic Cleaning No

Quartz (Chrysokoll Quartz)

Treatment None explanation N/A Care Instructions Clean with warm soapy water and a soft cloth. Store separately from other pieces of jewellery to avoid scratching. Steam Cleaning No Ultrasonic Cleaning No

Quartz (Crushed Ice Quartz)

Treatment Heating explanation To improve the polish and seal the surface Care Instructions Solvents can remove the wax layer and make the stone appear less polished. Steam Cleaning No Ultrasonic Cleaning No

Quartz (Dumortierite Quartz)

Treatment Waxing explanation To improve the polish and seal the surface" Care Instructions Solvents can remove the wax layer and make the stone appear less polished. Steam Cleaning Yes Ultrasonic Cleaning Yes

Quartz (Green Quartz)

Treatment Heating, irradiation and dyeing explanation Rarely used to improve appearance Care Instructions None Steam Cleaning No Ultrasonic Cleaning No

Quartz (Green Strawberry Quartz)

Treatment None or dyeing explanation N/A Care Instructions None Steam Cleaning No Ultrasonic Cleaning No

Quartz (Savanna Quartz)

Treatment Heating explanation Generally used to emphasise and improve colour Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning No

Quartz (Tibetan Quartz)

Treatment None explanation N/A Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning No

Quartz (Watermelon Quartz)

Treatment Compound gemstone, encased explanation Used for colour enhancement Care Instructions Keep away from heat and chemicals such as oils, perfume and household cleaners. Durable, stable and long-lasting if care instructions are followed. Steam Cleaning No Ultrasonic Cleaning No

Quartz (Azur Quartz, Champagne Mystik Quartz)

Treatment Irradiation explanation Generally used to evoke and/or enhance colour. Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning Yes

Quartz (Azur Quartz, Lilac Quartz)

Treatment Surface staining / diffusion explanation Generally used to improve/strengthen the colour or to create unique colours. Care Instructions Keep away from high temperatures. Steam Cleaning No Ultrasonic Cleaning No

Quartz (Blue-green Quartz, Forrest Green Quartz)

Treatment Dyeing / Diffusion explanation Generally used to improve/strengthen the colour or to create unique colours. Care Instructions Keep away from high temperatures. Steam Cleaning No Ultrasonic Cleaning No

Quartz (Cherry blossom Quartz, Green Mystic Quartz)

Treatment Surface treated, coated explanation Thin-film finishes consisting of various precious and semi-precious metals, oxides and nitrides, which are durable and long-lasting if the care instructions are followed. Finishing takes place according to environmentally friendly processes. No irradiation Care Instructions Clean with warm soapy water and a soft cloth. Rinse well to remove soap residues. Remove gemstone jewellery before sports, gardening or housework. Store individually to avoid scratches. Steam Cleaning No Ultrasonic Cleaning No

Quartz (Honey Quartz, Red Quartz)

Treatment None explanation N/A Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning Yes

Quartz (Anthracite Cat’s Eye Quartz, Cat's Eye Quartz, Yellow Quartz)

Treatment None explanation N/A Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning Yes

Quartz (Chocolate Quartz, Dinosaur Bone, Phantom Quartz, Psidium Quartz)

Treatment None explanation N/A Care Instructions Do not expose to extreme temperature fluctuations. Do not use harsh chemicals or cleaning liquids, especially bleach or acids. Clean with warm soapy water and soft cloth. Remove jewellery during sports and housework. Steam Cleaning No Ultrasonic Cleaning No

Quartz (Amazon Quartz, Blue Moon Quartz, Blueberry Quartz, Lily Quartz, Ouro Verde Quartz, White Quartz)

Treatment None or heated explanation Rarely used to improve appearance Care Instructions None Steam Cleaning No Ultrasonic Cleaning No

Quartz (Champagne Quartz, Cognac Quartz, Lemon Quartz, Mocha Quartz, Olive Quartz, Smoky Quartz)

Treatment Heating and/or irradiation explanation Rarely used to improve appearance Care Instructions None Steam Cleaning No Ultrasonic Cleaning No

Quartz (Moss Green Quartz, Navy Blue Quartz, Pacific Blue Quartz, Peach Quartz, Pink Quartz, Royal Blue Quartz)

Treatment Dyeing explanation Generally used to emphasise and improve colour Care Instructions Do not use aggressive chemicals or cleaning fluids, especially bleach or acids. Clean with warm soapy water and a soft cloth. Avoid contact with hot water. Remove jewelry when engaging in sports or household chores. Steam Cleaning No Ultrasonic Cleaning No

Quartz (Blue Pastel Quartz, Green Pastel Quartz, Orange Pastel Quartz, Peach Pastel Quartz, Pink Pastel Quartz, Purple Pastel Quartz, Purple Quartz, Yellow Pastel Quartz)

Treatment Heating / diffusion treatment explanation Generally used to improve/strengthen the colour or to create unique colours Care Instructions Keep away from high temperatures. Steam Cleaning No Ultrasonic Cleaning No

Quartz (Cognac Mystic Quartz, Fuchsia Quartz, Moonlight Quartz, Ocean Mystic Quartz, Purple Mystic Quartz, Siena Mystic Quartz, Sunset-Quarz, Yello Mystic Quartz)

Treatment CVD process explanation Commonly used to produce unique colors Care Instructions Do not expose to hot water Steam Cleaning No Ultrasonic Cleaning No

Quartz (Black Rutile Quartz, Cuprian Rutile Quartz, Herkimer quartz, Icemoon Quartz, Mutuca Rutile Quartz, Prase, Prince Quartz, Rose Quartz, Rutile Quartz, Sawar Rose Quartz, Strawberry Quartz, Tourmalinated Quartz)

Treatment None explanation N/A Care Instructions None Steam Cleaning No Ultrasonic Cleaning No

Quartz (Aurora Quartz, Bi Colour Quartz, Blue Mystik Quartz, Capri Quartz, Lavender Mystic Quartz, Luna quartz, Mountain Lake Quartz, Ocean Quartz, Orange Mystic Quartz, Oriental Red Quartz, Paraiba Quartz, Sky blue Quartz, Tundra Quartz)

Treatment Surface treated, coated explanation Thin-film finishing by vapour deposition of nanoparticles consisting of various precious and semi-precious metals (including gold), oxides and nitrides, which are durable and long-lasting if care instructions are followed. Environmentally friendly process without harmful chemicals. Care Instructions Clean with warm soapy water and a soft cloth. Rinse well to remove soap residues. Remove gemstone jewellery before sports, gardening or housework. Store individually to avoid scratches. Steam Cleaning No Ultrasonic Cleaning No

Quartz (Black Glitter Quartz, Bronze Glitter Quartz, Cobalt Blue Glitter Quartz, Cuprian Glitter Quartz, Cyan Quartz, Flamingo Glitter Quartz, Golden Glitter Quartz, Green Glitter Quartz, Mystik Quartz, Neptune Glitter Quartz, Peach Glitter Quartz, Pearl Glitter Quartz, Pink Glitter Quartz, Platinum Glitter Quartz, Purpur Glitter Quartz, Rainbow Quartz, Silver Glitter Quartz, Titan Blue Glitter Quartz)

Treatment Heating, irradiation, PVD-coating (PVD process): US Patent Number 5,853,826 for Asotic Coating Technologies Inc) and dyeing explanation Generally used to improve/strengthen the colour or to create unique colours. The physical coating with steam is an oxide treatment that uses optical interference to produce a variety of colours thanks to the application of a bonded layer of fine titanium atoms. Care Instructions Coated or surface-treated gemstones cannot be resharpened and polished. Steam Cleaning No Ultrasonic Cleaning No

Quartzite (Purple Quartzite)

Treatment Colouring and filling with plastic explanation Generally used to improve/strengthen the colour or to create unique colours. Care Instructions keep away from direct fire and heat Steam Cleaning Yes Ultrasonic Cleaning Yes

Quartzite (Quartzite)

Treatment Dyeing and/or impregnating with plastic or cured resin explanation Occasionally used to achieve a uniform colour Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning No

R

Rhodochrosite (Rhodochrosite)

Treatment None explanation N/A Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning No

Rhodonite (Brasilian Rhodonite, Rhodonite, Sulawesi Rhodonite)

Treatment None explanation N/A Care Instructions None Steam Cleaning No Ultrasonic Cleaning No

Rhyolite (Kabamba Rhyolite, Sunset Rhyolite)

Treatment None explanation N/A Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning Yes

Rubellite (AAA Brasisilan Rubellite, AAA Cruzeiro Rubellite, AAA Nigerian Rubellite, AAA Rubellite, AAA Shimoyo Rubellite, AAA-Zambezia-Rubellit, Brazilian Rubellite, Cat's Eye Shimoyo Rubellite, Cat's eye Rubellite, Cruzeiro-Rubellit, Cuprian Rubellite, Ibadan-Rubellit, Nigerian Rubellite, Rose Nigerian Rubellite, Rubellite, Shimoyo Rubellite, Sibirian Cat's Eye Rubellite, Zambezia Rubellite)

Treatment None or irradiated explanation N/A Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning No

Ruby (Channapatna-Star Ruby)

Treatment None explanation N/A Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning Yes

Ruby (Ruby)

Treatment Heating, possibly with the addition of colouring substances, and/or closure of cracks/cavities or introduction of additives (Beryllium) and/or colouring, rarely untreated explanation Generally used to create, intensify or lighten the colour and/or to improve the uniformity of the colour. The lead glass is usually yellow to orange and refines the natural red hue. Increased carat weight possible. In rare cases ruby is also coloured to improve the colour. Care Instructions Fillings in, gaps, cracks and/or open fractures can scratch more easily than the parent stone and are more susceptible to damage by heat or solvents. Steam Cleaning Yes Ultrasonic Cleaning Yes

Ruby (Thai Ruby)

Treatment Heating, possibly with the addition of colouring substances explanation Generally used to emphasise and improve colour Care Instructions Some stones fade or return to their original colour when exposed to strong light; do not expose the gemstones unnecessarily to these conditions for a long time Steam Cleaning No Ultrasonic Cleaning No

Ruby (Burmese Ruby, Johnson Ruby, Kenyan Ruby)

Treatment Heating explanation Generally used to emphasise and improve colour Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning Yes

Ruby (Star Ruby, Star Ruby (unheated), Star Ruby (unheated))

Treatment None or heating and/or oiling or dyeing and/or diffusion treatment explanation Star rubies are heated to improve or create asterism (star) or receive a diffusion treatment. Oiling and dyeing is used for colour enhancement and laminating of natural cracks. Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning Yes

Ruby (AAA Longido Ruby, AAA Mozambique Ruby, Morogoro Ruby, Siam Ruby)

Treatment Heating explanation Generally used to evoke and/or enhance colour. Care Instructions Clean with warm water Steam Cleaning Yes Ultrasonic Cleaning Yes

Ruby (Madagascar Ruby, Malawi Ruby, Sunset Ruby, Tanzanian Ruby)

Treatment Heating, possibly with the addition of colouring substances, and/or sealing of cracks / cavities or introduction of additives (Beryllium) explanation Generally used to create, intensify or lighten the colour and/or to improve the uniformity of the colour. Lead glass is usually yellow to orange and refines the natural red colour. Increased carat weight possible. Care Instructions Fillings in, gaps, cracks and/or open fractures can scratch more easily than the parent stone and are more susceptible to damage by heat or solvents. Steam Cleaning No Ultrasonic Cleaning No

Ruby (Bemainty Ruby, John Saul Ruby, Mozambique Cat's Eye Ruby, Mozambique Ruby, Mozambique Star Ruby)

Treatment Heating with a lead silicate with a high refractive index to fill fractures and cavities and/or introduction of various additives (beryllium) explanation Always used to intensify the colour, lighten and/or improve uniformity, may have an effect on the carat weight. The lead silicate is usually yellow or orange and intensifies the red colour of the gemstone. Care Instructions Fillings in, gaps, cracks and/or open fractures can scratch more easily than the parent stone and are more susceptible to damage by heat or solvents. Steam Cleaning Yes Ultrasonic Cleaning Yes

S

Saffordite (Saffordite)

Treatment None explanation N/A Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning No

Sapphire (Blue Sapphire)

Treatment Heating (heated in an environment containing Beryllium and may contain traces of Beryllium) and/or sealing of cracks/cavities or introduction of additives (Beryllium) and/or dyeing explanation It is generally used to produce the colour and/or achieve its uniformity and to intensify or lighten the colour. In rare cases the sapphire is dyed to improve the colour. Care Instructions Fillings in, gaps, cracks and/or open fractures can scratch more easily than the parent stone and are more susceptible to damage by heat or solvents. Steam Cleaning No Ultrasonic Cleaning Yes

Sapphire (Blue Star Sapphire)

Treatment None or heating and/or oiling or dyeing and/or diffusion treatment explanation Blue star sapphires are heated to improve or produce asterism (star), receive a diffusion treatment; oiling and dyeing is used to enhance colour and conceal natural cracks Care Instructions None Steam Cleaning No Ultrasonic Cleaning No

Sapphire (Midnight Blue Sapphire)

Treatment Heating (heated in a Beryllium-containing environment and may contain traces of Beryllium) and/or sealing cracks/cavities or introducing additives (Beryllium). In rare cases coloured. explanation Generally used to create the colour or its uniformity, to intensify or lighten the colour. Care Instructions Fillings in, gaps, cracks and/or open fractures can scratch more easily than the parent stone and are more susceptible to damage by heat or solvents. Steam Cleaning No Ultrasonic Cleaning Yes

Sapphire (AAA Tanzanian Sapphire, Blue Mozambique Sapphire)

Treatment None explanation N/A Care Instructions None Steam Cleaning No Ultrasonic Cleaning No

Sapphire (Blue Bemainty Sapphire, Pink Madagascar Sapphire)

Treatment Heating with a lead silicate to fill cracks and cavities. explanation Always used to intensify the colour, lighten and/or improve uniformity, can have an effect on the carat weight. Care Instructions Fillings in, gaps, cracks and/or open fractures can scratch more easily than the parent stone and are more susceptible to damage by heat or solvents. Steam Cleaning Yes Ultrasonic Cleaning No

Sapphire (Blue Madagascar Sapphire, Yellow Madagascar Sapphire)

Treatment Dyeing and heating with a lead silicate to fill cracks and cavities. explanation Always used to intensify the colour, lighten and/or improve uniformity, can have an effect on the carat weight. Care Instructions Fillings in cavities, gaps, cracks and/or open fractures can be more easily scratched than the mother stone and are more susceptible to damage from heat or solvents. Steam Cleaning Yes Ultrasonic Cleaning No

Sapphire (Honey Sapphire, Unheated Blue Ceylon Sapphire)

Treatment None explanation N/A Care Instructions Clean with warm soapy water and a soft cloth or soft toothbrush. Do not use aggressive chemicals or cleaning fluids. Steam Cleaning No Ultrasonic Cleaning No

Sapphire (Anthracite Sapphire, Australian Green Saphire, Australian Sapphire, Chocolate Sapphire)

Treatment None explanation N/A Care Instructions Avoid anything containing moisturisers, abrasives or antistatic agents, as these can leave residues and cause scratches. Clean with water and a soft toothbrush. Steam Cleaning No Ultrasonic Cleaning No

Sapphire (Burmese Sapphire, Fancy Ceylon Sapphire, Laos Sapphire, Montana Sapphire, Mozambique Sapphire, Oranger Ceylon Sapphire, Purlpe Umba Sapphire, Yellow Ceylon Sapphire)

Treatment Heating explanation Commonly used to create and enhance colour Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning Yes

Sapphire (Acacia green Queensland Sapphire, Black Sapphire, Black Star Sapphire, Carribean Teal Queensland Sapphire, French Sapphire, Green Ceylon Sapphire, Green Queensland Sapphire, Yellow Queensland Sapphire, Yellow Star Sapphire)

Treatment None explanation N/A Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning Yes

Sapphire (AAA Green Sapphire, Ban Ka Cha Orange Sapphire, Ban Ka Cha Yellow Sapphire, Blue Ceylon Sapphire, Ceylon Sapphire, Colour Change Sapphire, Ethiopian Sapphire, Kanchanaburi Sapphire, Orange Sapphire, Padparadscha Sapphire, Pink Sapphire, Sunset Sapphire, Tanzanian Sapphire, White Sapphire, Yellow Sapphire)

Treatment Heating (might be heated in a Beryllium-containing environment and may contain traces of Beryllium) and/or sealing cracks/cavities or introducing additives (Beryllium) explanation Generally used to create the colour or its uniformity, to intensify or lighten the colour. Care Instructions Fillings in, gaps, cracks and/or open fractures can scratch more easily than the parent stone and are more susceptible to damage by heat or solvents. Steam Cleaning No Ultrasonic Cleaning Yes

Sardonyx (Sardonyx)

Treatment None explanation N/A Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning Yes

Scapolite (Cognac Skapolite)

Treatment Irradiation explanation Commonly used to create and enhance colour Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning No

Scapolite (Burmese Scapolite, Cat's Eye Scapolite, Mogok-Skapolith, Pink Skapolite, Purlpe Skapolite, Scapolite, Yellow Scapolite)

Treatment None explanation N/A Care Instructions Some stones fade when exposed to strong light; do not expose the gemstones unnecessarily long to these conditions. Steam Cleaning Yes Ultrasonic Cleaning No

Selenite (Alabaster Selenite)

Treatment Waxing. Commonly used to improve the appearance explanation For sealing the surface Care Instructions soft and delicate stone, can be easily scratched. Handle with care. Steam Cleaning No Ultrasonic Cleaning No

Selenite (Selenite)

Treatment None explanation N/A Care Instructions soft and delicate stone, can be easily scratched. Handle with care. Steam Cleaning No Ultrasonic Cleaning No

Seraphinite (Seraphinite)

Treatment None explanation N/A Care Instructions Very fragile; treat with great care Steam Cleaning Yes Ultrasonic Cleaning No

Shattuckite (Shattuckite)

Treatment none or filling of fissures during grinding and polishing explanation Sealing the fissures prevents the abrasive material and polishing powder from sticking to stone surfaces. Care Instructions Do not store together with harder stones, risk of scratching. Steam Cleaning No Ultrasonic Cleaning No

Shell (Abalone Shell Mosaic)

Treatment Assembling abalone shell pieces using resin explanation To make the mosaic Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning No

Shell (Capiz Shell, Orange Spiny Oyster)

Treatment None explanation N/A Care Instructions None Steam Cleaning No Ultrasonic Cleaning No

Shell (Abalone Shell, Mother of Pearl, Pink shell)

Treatment Dyeing, bleaching and/or coating explanation Frequently used to create or enhance colour Care Instructions Some stones fade or return to their original colour when exposed to strong light; do not expose the gemstones to these conditions unnecessarily long. Please keep away from acidic cosmetics and all detergents. Steam Cleaning No Ultrasonic Cleaning No

Sillimanite (Star Sillimanite)

Treatment none explanation N/A Care Instructions none Steam Cleaning No Ultrasonic Cleaning No

Sodalite (Sodalite)

Treatment Dyeing explanation Rarely used to improve colour Care Instructions Some stones fade or return to their original colour when exposed to strong light; do not expose the gemstones unnecessarily to these conditions for a long time Steam Cleaning No Ultrasonic Cleaning No

Spectrolite (Spectrolite)

Treatment Surface waxing explanation Used to improve the look and feel of the product. Care Instructions None Steam Cleaning No Ultrasonic Cleaning No

Sphalerite (Bulgarian Green Sphalerite, Mint-Sphalerite, Sphalerite)

Treatment None explanation N/A Care Instructions Very fragile; treat with great care Steam Cleaning No Ultrasonic Cleaning No

Sphene (Capelinha Sphene, Chrome Sphene, Russian Sphen, Sphene, Zimbabwe Sphene)

Treatment None explanation N/A Care Instructions None Steam Cleaning No Ultrasonic Cleaning No

Spinel (Black Mystic Spinel)

Treatment Coating explanation The coating is produced by placing in a rhodium bath which produces a special surface gloss. Care Instructions Coated or surface-treated gemstones cannot be resharpened and polished. Steam Cleaning Yes Ultrasonic Cleaning No

Spinel (Royal Blue Spinel)

Treatment Heating (are heated in a cobalt-containing environment and may contain traces of cobalt) and/or sealing of cracks/cavities or introduction of additives (cobalt) explanation Used to bring out the colour or its uniformity, to intensify or lighten the colour Care Instructions Clean with warm soapy water and a soft cloth. Store separately from other pieces of jewellery to avoid scratching. Steam Cleaning No Ultrasonic Cleaning No

Spinel (Black Spinel, Colorchange Spinel, Mahenge Purple Spinel, Noble Red Spinel, Pamir Spinel, Pink Mahenge Spinel, Pink Spinel)

Treatment None explanation N/A Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning No

Spinel (Cobalt Blue Luc Yen Spinel, Green Luc Yen Spinel, Lavender Luc Yen Spinel, Noble Red Luc Yen Spinel, Pink Luc Yen Spinel, Platin Luc Yen Spinel, Purple Luc Yen Spinel)

Treatment None explanation N/A Care Instructions Cleaning with warm soapy water and a soft cloth. Steam Cleaning No Ultrasonic Cleaning No

Stalactite (Stalactite)

Treatment lacquered in engraving areas explanation For surface protection and polished appearance Care Instructions soft and delicate stone, can be easily scratched. Handle with care. Steam Cleaning No Ultrasonic Cleaning No

Stichtite (Stichtite)

Treatment Filling fissures with transparent resin explanation For sealing the surface Care Instructions Clean with a soft cloth. void the use of alcohol and other aggressive chemicals. Steam Cleaning No Ultrasonic Cleaning Yes

Sugilite (Sugilite)

Treatment None explanation N/A Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning No

Sunstone (Australian Sunstone)

Treatment Filling fissures with resin explanation For stabilisation during grinding and polishing Care Instructions With some stones, a temperature shock can lead to damage; do not expose to extreme temperature fluctuations. Do not use harsh chemicals or cleaning liquids, especially bleach or acids. Clean with warm soapy water and soft cloth. Steam Cleaning No Ultrasonic Cleaning No

Sunstone (Cat's Eye Sunstone, Moon Sunstone, Oregon Sunstone, Silver Sunstone, Star Sunstone, Sunstone, Tanzanian Cat's Eye Sunstone, Tanzanian Star Sunstone, Tanzanian Sunstone)

Treatment None explanation N/A Care Instructions With some stones, a temperature shock can lead to damage; do not expose to extreme temperature fluctuations. Do not use harsh chemicals or cleaning liquids, especially bleach or acids. Clean with warm soapy water and soft cloth. Steam Cleaning No Ultrasonic Cleaning No

T

Tanzanite (AAA Tanzanite, Blue-Green Tanzanite, Tanzanite)

Treatment Heating explanation Used to enhance or evoke the desired colour Care Instructions Do not expose to extreme temperature fluctuations Steam Cleaning No Ultrasonic Cleaning No

Tanzanite (Chameleon Tanzanite, Emerald green Tanzanite, Green Tanzanite, Unheated Green Tanzanite)

Treatment None or heated explanation Used to enhance or evoke the desired colour Care Instructions Do not expose to extreme temperature fluctuations Steam Cleaning No Ultrasonic Cleaning No

Tanzanite (AAA-Gelber Tansanit, Magentafarbener Tansanit, Pink Tanzanite, Unheated Pink Tanzanite, Unheated Tanzanite, Yellow Tanzanite)

Treatment None explanation N/A Care Instructions Do not expose to extreme temperature fluctuations Steam Cleaning No Ultrasonic Cleaning No

Tektite (Indochinite)

Treatment None explanation N/A Care Instructions None Steam Cleaning No Ultrasonic Cleaning No

Thulite (Thulite)

Treatment None explanation N/A Care Instructions Softly clean with mild soap, soft toothbrush and lukewarm water. After cleaning dry with a soft cloth or chamois leather. Steam Cleaning No Ultrasonic Cleaning No

Tibetanit (Green Tibetanite, Roter Tibetanite)

Treatment None explanation N/A Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning No

Tigers Eye (Black Tigers Eye)

Treatment Heating explanation Generally used to improve the colour Care Instructions Keep away from alkaline substances and heat Steam Cleaning No Ultrasonic Cleaning No

Tigers Eye (Blue Tigers Eye, Golden Tigers Eye)

Treatment None explanation N/A Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning Yes

Tigers Eye (Red Tigers Eye, Tigers Eye)

Treatment None or bleaching, dyeing and/or heating explanation Used to enhance or evoke the desired colour Care Instructions Some stones fade or return to their original colour when exposed to strong light; do not expose the gemstones unnecessarily to these conditions for a long time Steam Cleaning No Ultrasonic Cleaning No

Topaz (Ouro Preto Imperial Topaz, Ouro Preto Pink Topaz)

Treatment Heating explanation Used for colour enhancement Care Instructions None Steam Cleaning No Ultrasonic Cleaning No

Topaz (Farngrüner Topas, Kiwi Topaz, Mandarin Topaz)

Treatment CVD process explanation Commonly used to produce unique colors Care Instructions Nicht in Verbindung mit heißem Wasser bringen translates to "Do not expose to hot water" Steam Cleaning No Ultrasonic Cleaning No

Topaz (AAA Imperial Topaz, Imperial Katlang Topaz, Imperial Topaz, Multicoloured Ukranian Topaz, Royal White Topaz, Vermillion Imperial Topaz)

Treatment None explanation N/A Care Instructions None Steam Cleaning No Ultrasonic Cleaning No

Topaz (Anniversary Topas, Lotus Flower Topas, Morning Dew Topas, Peach coloured Mystic Topaz, Purple Mystic Topaz, Rainbow Topaz, Royal Blue Topaz, Siena Mystic Topaz)

Treatment Surface treated, coated explanation Thin-film finishing by vapour deposition of nanoparticles consisting of various precious and semi-precious metals (including gold), oxides and nitrides, which are durable and long-lasting if care instructions are followed. Environmentally friendly process without harmful chemicals. Care Instructions Clean with warm soapy water and a soft cloth. Rinse well to remove soap residues. Remove gemstone jewellery before sports, gardening or housework. Store individually to avoid scratches. Steam Cleaning No Ultrasonic Cleaning No

Topaz (Bi Colour Topaz, Blue Topaz, Indigo blue Topaz, London Blue Topaz, Marambaia Topaz, Sky Blue Topaz, Swiss Blue Topaz, White Topaz)

Treatment Heating and/or irradiation explanation Generally used to create and/or enhance colour. Care Instructions None Steam Cleaning No Ultrasonic Cleaning No

Topaz (Blue Mystik Topaz, Canari Topaz, Capri Topaz, Flamingo Topaz, Glacier Topaz, Grape Topaz, Jungle Topaz, Kiwi Topaz, Moonlight Topaz, Moonlight Topaz, Mystic Topaz, Neon Blue Mystik Topaz, Neptune Topaz, Paraíba Topas, Pink Topaz, Purple Topaz, Red Topas, Rose Topaz, Sunset Mystic Topaz, Sunset Topaz)

Treatment Heating, irradiation and PVD-coating (PVD process): US Patent Number 5,853,826 for Asotic Coating Technologies Inc) explanation Generally used to improve/strengthen the colour or to create unique colours. The physical coating with steam is an oxide treatment that uses optical interference to produce a variety of colours thanks to the application of a bonded layer of fine titanium atoms. Care Instructions Some stones fade or revert to their original colour when exposed to strong light; gemstones are not unnecessarily exposed to these conditions; coated or surface-treated gemstones cannot be resharpened and polished Steam Cleaning No Ultrasonic Cleaning No

Topazolite (Topazolite)

Treatment None explanation N/A Care Instructions Do not expose to extreme temperature fluctuations Steam Cleaning No Ultrasonic Cleaning No

Tourmaline (Cat's Eye Indicolite)

Treatment None explanation N/A Care Instructions Do not use harsh chemicals or cleaning liquids, do not expose to extreme temperatures. Protect from knocks or scratches, this can damage the surface. Steam Cleaning No Ultrasonic Cleaning No

Tourmaline (Green Golconda Tourmaline)

Treatment None explanation N/A Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning Yes

Tourmaline (Tourmaline)

Treatment none or stabilizing and impregnating with polymers and waxes explanation Stabilizing and impregnating reduces porosity and improves shine and surface of small tourmalines in bead necklaces. Care Instructions None Steam Cleaning No Ultrasonic Cleaning No

Tourmaline (Chocolate Tourmaline, Congo Neon Tourmaline)

Treatment Irradiation explanation Generally used to create and/or enhance colour. Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning Yes

Tourmaline (Cat's Eye Paraiba Tourmaline, Cat's Eye Pirineu Tourmaline, Cat's Eye Tourmaline)

Treatment none or acid treatment and/or impregnation with polymers or epoxy explanation The cat's eye effect (chatoyance) can be more visible through the acid treatment. The surfaces are impregnated to make the stone more durable and to protect it from contamination. Care Instructions None Steam Cleaning No Ultrasonic Cleaning No

Tourmaline (AAA-Mutuca-Indigolite, Bi Colour Mutuca Indicolite, Cat's Eye Mutuca Indicolite, Indicolite, Mutuca Indicolite, Santa Rosa Tourmaline)

Treatment None or heated explanation N/A Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning No

Tourmaline (AAA Paraíba Tourmaline, Afghan Olive Tourmaline, Afghan Tourmaline, Brazilian Paraíba Tourmaline, Brazilian Tourmaline, Chrome Tourmaline, Cuprian Tourmaline, Morro Redondo Pink Tourmaline, Morro Redondo Tourmaline, Namibian Tourmaline, Nigerian Paraiba Tourmaline, Paraíba Tourmaline, Pink Tourmaline, Yellow Tourmaline)

Treatment None or heating and/or irradiation explanation N/A Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning No

Tourmaline (AAA Pink Tourmaline, Blue Green Sapo Tourmaline, Carribean Teal Tourmaline, Cat's Eye Pirineu Tourmaline, Denim Tourmaline, Green Tourmaline, Imperial Chrome Tourmaline, Lagoon Tourmaline, Maine Tourmaline, Mint Namibian Tourmaline, Neon-Turmalin, Nigerian Tourmaline, Olive Tourmaline, Pink California Tourmaline, Pink Cuprian Tourmaline, Pink Sapo Tourmaline, Pirineu Tourmaline, Purlpe Tourmaline, Red Cuprian Tourmaline, Red Sapo Tourmaline, Watermelon Tourmaline, Yellow Tourmaline)

Treatment None explanation N/A Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning No

Turquoise (African Turquoise)

Treatment None explanation N/A Care Instructions None Steam Cleaning No Ultrasonic Cleaning No

Turquoise (Sleeping Beauty Turquoise)

Treatment Zachary Treatment explanation For stabilisation without adding artificial components such as dyes or polymer fillers. Stone is not hardened or put under pressure. Removes impurities without the use of polymers/resins. Increases resistance to discolouration, allows for improved polish and colour. Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning No

Turquoise (Tibetan Turquoise)

Treatment None explanation N/A Care Instructions Remove jewellery during sports and housework. Keep away from heat and chemicals such as oils, perfume and household cleaners. Steam Cleaning No Ultrasonic Cleaning No

Turquoise (Turquoise Mosaic)

Treatment stabilised turquoise chips with resin composite explanation To make the mosaic Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning No

Turquoise (Bisbee Turquoise, Green New Lander Turquoise, Morenci Turquoise, Peruan Turquoise)

Treatment None explanation N/A Care Instructions Clean with warm soapy water. Keep away from heat and chemicals such as oils, perfume and household cleaners. Avoid the use of commercially available jewellery cleaners. Steam Cleaning No Ultrasonic Cleaning No

Turquoise (Blue Kingman Mohave-Turquoise, Blue Mohave Cuprian Turquoise, Green Kingman Mohave-Turquoise, Mohave Turquoise, Orange Kingman Mohave Turquoise, Purple Mohave copper turquoise, Violet Kingman Mohave-Turquoise)

Treatment Stabilisation and impregnation with copper particles or other metal particles and polymers and dyeing explanation Turquoise particles with copper particles and polymers are processed into this material to improve colour and create a more beautiful pattern. The orange and purple stones are coloured to create the desired colour. Care Instructions None Steam Cleaning No Ultrasonic Cleaning No

Turquoise (Arizona Turquoise, Blue Copper Turquoise, Blue Turquoise, Campitos Turquoise, Carico Lake Turquoise, Kingman Turquoise, Purple copper turquoise, Purpur Turquoise, Sonora Turquoise, South Western Turquoise, Turquoise, Tyrone Turquoise)

Treatment mostly stabilisation and impregnation with colourless polymers and waxes, in a few cases dyeing, partially reconstructed explanation Untreated turquoise is rarely sold in the jewellery industry. Stabilising and impregnating reduces porosity and improves gloss and surface finish. In some cases, turquoise particles are processed with polymers to produce a more uniform colour. Care Instructions None Steam Cleaning No Ultrasonic Cleaning No

U

Unakit (Unakit)

Treatment None explanation N/A Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning Yes

V

Variscite (Variscite)

Treatment None explanation N/A Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning Yes

Vesuvianite (Vesuvianite)

Treatment None explanation N/A Care Instructions None Steam Cleaning Yes Ultrasonic Cleaning Yes

Z

Zarinite (Zarinite)

Treatment Sealing cracks with resin. explanation to improve the grinding properties Care Instructions None Steam Cleaning No Ultrasonic Cleaning No

Zeolite (Natrolite)

Treatment None explanation N/A Care Instructions Relatively soft gemstone, store separately to avoid scratches Steam Cleaning No Ultrasonic Cleaning No

Zircon (Raspberry Zircon)

Treatment None explanation N/A Care Instructions Some stones fade when exposed to strong light; do not expose the gemstones unnecessarily long to these conditions. Steam Cleaning No Ultrasonic Cleaning No

Zircon (Carribean Teal Zircon, Mandarin Zircon, Sunset Zircon, Yellow Zircon)

Treatment Heating explanation Used for colour enhancement Care Instructions Some stones fade when exposed to strong light; do not expose the gemstones unnecessarily long to these conditions. Steam Cleaning No Ultrasonic Cleaning No

Zircon (Chocolate Zircon, Imperial Zircon, Orange Mashewa Zircon, Orange Zircon)

Treatment None explanation N/A Care Instructions Some stones fade when exposed to strong light; do not expose the gemstones unnecessarily long to these conditions. Steam Cleaning Yes Ultrasonic Cleaning No

Zircon (Champagne Zircon, Cinnamon Zircon, Fancy Zircon, Pink Zircon, Zircon)

Treatment None or heated explanation Used to improve the colour Care Instructions Some stones fade when exposed to strong light; do not expose the gemstones unnecessarily long to these conditions. Steam Cleaning Yes Ultrasonic Cleaning No

Zircon (AAA Ratanakiri Zircon, Blue Zircon, Hartsite Zircon, Kaduna Zircon, Preah Vihear Zircon, Ratanakiri Zircon, Red Zircon, White Zircon)

Treatment Heating explanation Used to improve the colour Care Instructions Some stones fade when exposed to strong light; do not expose the gemstones unnecessarily long to these conditions. Steam Cleaning Yes Ultrasonic Cleaning No

Zoisit (Ruby in Zoisite)

Treatment None explanation N/A Care Instructions None Steam Cleaning No Ultrasonic Cleaning Yes

Zultanite (Cat's Eye Zultanite, Zultanite)

Treatment None explanation N/A Care Instructions None Steam Cleaning No Ultrasonic Cleaning No
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