| Gemstone |
Enhancement |
Explanation & Frequency |
Special Care Instructions |
Steam Cleaning |
Ultrasonic Cleaning |
| Actinolite (including Cat's Eye) |
Natural. |
N/A |
None. |
 |
 |
| Agate (including Fire) |
Natural. |
N/A |
None. |
 |
 |
Alexandrite (including Cat's Eye) |
Natural. |
N/A |
None. |
 |
 |
| Alexandrite |
Natural. |
N/A |
None. |
 |
 |
| Amazonite |
Colourless wax or oil, paraffin or hardened resin and/or impregnated
with colourless plastic or hardened resin. |
Impregnation with colourless plastic or hardened resin is occasional,
while colourless wax or oil, paraffin or hardened resin is usual. All improve
appearance. |
None. |
 |
 |
| Amber |
Heated. |
Usually applied to improve appearance and/or deepen colour. |
Clean by gently wiping with a moist cloth. |
 |
 |
| Amblygonite |
Natural. |
N/A |
Can be damaged by thermal shock, do not expose to extreme temperature
changes. |
 |
 |
| Amethyst (including Bi Colour, Platina and Rose de France) |
Heated. |
Occasionally used to lighten colour and/or remove smokiness. |
Do not wear or leave for extended periods in strong light as these gems may fade or revert to their original colour. |
 |
 |
| Amethyst (Green and Rio Grande Green) |
Heated and/or irradiated. |
Usually applied to provide/improve colour and appearance. |
None. |
 |
 |
| Amethyst (Uruguayan and Zambian) |
Natural. |
N/A |
None. |
 |
 |
| Ametrine (including Sunburst) |
Heated. |
Rarely applied to improve colour. |
None. |
 |
 |
| Ametrine |
Heated. |
Rarely applied to improve colour. |
None. |
 |
 |
| Andalusite |
Natural. |
N/A |
None. |
 |
 |
| Andesine |
Heated and/or diffused. |
Sometimes applied to provide/improve colour. |
None. |
 |
 |
| Anglesite |
Natural. |
N/A |
Handle with care, very fragile. |
 |
 |
| Apatite (including Caribbean Blue and Neon Blue) |
Heated. |
Usually applied to improve appearance and/or deepen colour. |
None. |
 |
 |
| Aquamarine (including AAA, Santa Maria, Santa Teresa and São Domingos) |
Heated. |
Usually applied to remove yellow or green components to produce a purer blue colour. |
None. |
 |
 |
Aquamarine
(Cat's Eye) |
Natural. |
N/A |
None. |
 |
 |
| Aragonite (including Capillitas) |
Natural. |
N/A |
None. |
 |
 |
| Aventurine |
Natural. |
N/A |
None. |
 |
 |
| Aventurine (Black) |
Irradiated. |
Usually applied to provide colour. |
None. |
 |
 |
| Axinite |
Natural. |
N/A |
None. |
 |
 |
| Azurmalachite (also known as Azurite Malachite) |
Surface waxing and/or impregnated with colourless plastic or hardened
resin. |
Impregnation with colourless plastic or hardened resin is rare, while
surface waxing is common. All improve stability, durability, lustre and/or
colour. |
None. |
 |
 |
| Beryl (Seafoam) |
Natural. |
N/A |
None. |
 |
 |
| Beryl (Yellow) |
Heated or irradiated. |
Usually applied to improve or provide colour. |
Do not wear or leave for extended periods in strong light as these
gems may fade or revert to their original colour. |
 |
 |
| Bixbite |
Colourless oil and resin. |
Commonly used to improve appearance. |
None. |
 |
 |
| Bloodstone |
Natural. |
N/A |
None. |
 |
 |
| Bronzite |
Natural. |
N/A |
None. |
 |
 |
| Carnelian |
Heated and/or dyed. |
Dyeing is occasional, while heating is usual. All produce colour.
|
Do not wear or leave for extended periods in strong light as these gems
may fade or revert to their original colour. |
 |
 |
| Calcite |
Natural. |
N/A |
Handle with care, very fragile. |
 |
 |
| Chalcedony |
Dyed. |
Commonly used to improve colour. |
Do not wear or leave for extended periods in strong light as these gems
may fade or revert to their original colour. |
 |
 |
| Chondrodite |
Natural. |
N/A |
None. |
 |
 |
| Chrysoberyl (including Cat's Eye and Tunduru) |
Natural. |
N/A. |
None. |
 |
 |
| Chrysocolla |
Surface colourless waxing and/or impregnation with colourless plastic
or hardened resin. |
Occasionally used to improve appearance. |
None. |
 |
 |
| Chrysoprase |
Natural. |
N/A |
None. |
 |
 |
| Citrine (including Bi Colour and Lemon) |
Heated or irradiated. |
Usually applied to produce colour. |
Do not wear or leave for extended periods in strong light as these gems
may fade or revert to their original colour. |
 |
 |
| Citrine (Mandarin) |
Heated. |
Usually applied to produce colour. |
Do not wear or leave for extended periods in strong light as these
gems may fade or revert to their original colour. |
 |
 |
| Clinohumite |
Natural. |
N/A |
None. |
 |
 |
| Danburite (including Pink and White) |
Heated. |
Commonly used to improve appearance. |
None. |
 |
 |
| Danburite (Brown) |
Irradiated. |
Commonly used to improve appearance. |
None. |
 |
 |
| Danburite (Cat's Eye) |
Natural. |
N/A |
None. |
 |
 |
| Diamond (all Colour Enhanced Diamonds including Black, Blue, Champagne,
Green, Pink, Red and Yellow) |
Irradiated and/or heated. |
Always used to improve colour intensity or to produce unique colours.
|
None. |
 |
 |
| Diamond (White) |
Natural. |
N/A |
None. |
 |
 |
| Diopside (including Russian and Star) |
Natural. |
N/A |
None. |
 |
 |
| Dumortierite |
Natural. |
N/A |
None. |
 |
 |
| Emerald (including AAA and Colombian) |
Colourless oil, polymer, wax and/or resin in fissures, and/or open fractures
or cavities filled with hardened resin. |
Colourless oil, polymer, wax and/or resin in fissures are usual and
open fractures or cavities filled with hardened resin is common. All improve
appearance. |
These enhancements can be damaged by some solvents and thermal shock.
Do not expose to extreme temperature changes. |
 |
 |
| Emerald (Trapiche) |
Natural. |
N/A |
None. |
 |
 |
| Epidote |
Natural. |
N/A |
None. |
 |
 |
| Fluorite (including Bi Colour, Colour Change, Capillitas and White) |
Natural. |
N/A |
None. |
 |
 |
| Fluorite (including Blue, Green, Purple, Red and Yellow) |
Irradiated. |
Commonly used to improve or provide colour. |
None. |
 |
 |
| Gahnite |
Natural. |
N/A |
None. |
 |
 |
| Garnet (including AAA Tsavorite, Andradite, Blue Colour Change, Colour Change, Demantoid, Hessonite, Kamtonga Colour Change, Madagascan Demantoid, Malaia, Mali, Mandarin, Merelani Mint, Mozambique, Pyrope, Rhodolite, Spessartite, Tsavorite and Umbalite) |
Natural. |
N/A |
Can be damaged by thermal shock, do not expose to extreme temperature changes. |
 |
 |
| Goshenite |
Natural. |
N/A |
None. |
 |
 |
| Hawk's Eye |
Natural. |
N/A |
None. |
 |
 |
| Heliodor |
Irradiated. |
Usually applied to provide colour. |
Do not wear or leave for extended periods in strong light as these gems
may fade or revert to their original colour. |
 |
 |
| Heliodor (Cat's Eye) |
Natural. |
N/A |
Do not wear or leave for extended periods in strong light as these gems
may fade or revert to their original colour. |
 |
 |
| Hematite |
Natural. |
N/A |
None. |
 |
 |
| Hiddenite |
Irradiated. |
Rarely used to improve and/or provide colour and uniformity. |
Do not wear or leave for extended periods in strong light as these gems
may fade or revert to their original colour. |
 |
 |
| Howlite (Blue) |
Dyed. |
Commonly used to imitate Turquoise or Lapis Lazuli. |
None. |
 |
 |
| Howlite (White) |
Natural. |
N/A |
None. |
 |
 |
| Idocrase |
Natural. |
N/A |
None. |
 |
 |
| Iolite (including Ceylon) |
Natural. |
N/A |
None. |
 |
 |
| Jade (Jadeite) |
Colourless polymer impregnation and/or polymer and colourless polymer
impregnation followed by acid treatment and/or dyed. |
Commonly used to improve colour and uniformity. |
None. |
 |
 |
| Jade (Nephrite) |
Dyed and/or impregnated with colourless oil, wax or resin. |
Rarely used to improve colour and uniformity. |
None. |
 |
 |
| Jade (Cat's Eye Nephrite) |
Natural. |
N/A |
None. |
 |
 |
| Jasper |
Dyed. |
Commonly used to imitate other gemstones. |
Do not wear or leave for extended periods in strong light as these gems
may fade or revert to their original colour. |
 |
 |
| Kornerupine |
Natural. |
N/A |
None. |
 |
 |
| Kunzite (Bi Colour) |
Natural. |
N/A |
Do not wear or leave for extended periods in strong light as these
gems may fade. |
 |
 |
| Kunzite (including Green, White and Yellow) |
Heated or irradiated. |
Commonly used to improve and/or darken colour. |
Do not wear or leave for extended periods in strong light as these gems
may fade or revert to their original colour. |
 |
 |
| Kunzite (Patroke) |
Heated. |
Commonly used to improve and/or darken colour. |
Do not wear or leave for extended periods in strong light as these
gems may fade or revert to their original colour. |
 |
 |
| Kyanite |
Natural. |
N/A |
None. |
 |
 |
| Labradorite |
Surface colourless waxing. |
Occasionally used to improve appearance. |
None. |
 |
 |
| Lapis Lazuli |
Surface colourless waxing and/or dyed. |
Commonly used to provide colour and/or colour uniformity. |
None. |
 |
 |
| Malachite |
Surface colourless waxing and/or impregnated with colourless plastic
or hardened resin. |
Impregnation with colourless plastic or hardened resin is rare, while
surface colourless waxing and/or coating with colourless wax is occasional.
All improve colour. |
None. |
 |
 |
| Marcasite |
Natural. |
N/A |
None. |
 |
 |
| Moldavite |
Natural. |
N/A |
None. |
 |
 |
| Mookite |
Heated. |
Always necessary for cutting. |
None. |
 |
 |
| Moonstone (including Rainbow) |
Natural. |
N/A |
None. |
 |
 |
| Morganite (including Bi Colour) |
Heated or irradiated. |
Commonly used to eliminate yellow overtones. |
None. |
 |
 |
| Mother of Pearl |
Coated, dyed or bleached. |
Occasionally used to improve and/or change colour and/or colour uniformity.
|
Clean by gently wiping with a moist cloth. |
 |
 |
| Obsidian (including Snowflake) |
Natural. |
N/A |
None. |
 |
 |
| Onyx |
Dyed. |
Always used to achieve colour uniformity. |
None. |
 |
 |
| Opal (including Blue, Blue Fire, Fire, Green, Jelly, Mexican Fire, Pink,
Semi Black, Yellow and White) |
Natural. |
N/A |
Keep away from heat and drying environments, these gems can crack if
they lose structural water. Can be damaged by thermal shock, do not expose
to extreme temperature changes. |
 |
 |
| Opal (Boulder) |
Infusion of unhardened colourless substances into voids. |
Occasionally used to improve appearance. |
Keep away from heat and drying environments, these gems can crack if
they lose structural water. Can be damaged by thermal shock, do not expose
to extreme temperature changes. |
 |
 |
| Opal (Matrix) |
Heated with organic substances. |
Always used to improve appearance. |
Keep away from heat and drying environments, these gems can crack if
they lose structural water. Can be damaged by thermal shock, do not expose
to extreme temperature changes. |
 |
 |
| Orthoclase |
Natural. |
N/A |
None. |
 |
 |
| Pearl (including Freshwater, Tahitian and South Sea) |
Bleached, dyed, chemically enhanced or irradiated. All our Pearls
are cultured. |
Occasionally used to improve and/or change colour and/or colour
uniformity. |
Clean by gently wiping with a moist cloth. |
 |
 |
| Pearl (Mabe) |
A Mabe Pearl is a hemispherical shaped Pearl that is grown against the
inside of the oyster's shell and is cut out of the shell with a circle-bit
drill. The nucleus is replaced with resin and the back capped with a piece
of Mother of Pearl. It can also be bleached, dyed, chemically treated or
irradiated. These Pearls are classified as composite gemstones. |
Always used to create this gemstone. |
Clean by gently wiping with a moist cloth. |
 |
 |
| Peridot |
Heat, colourless oil, wax or resin in fissures and/or filled fractures
with colourless hardened resin. |
Rarely used to improve appearance. |
Can be damaged by thermal shock, do not expose to extreme temperature
changes. |
 |
 |
| Peridot (Kashmir) |
Natural. |
N/A |
Can be damaged by thermal shock, do not expose to extreme temperature changes. |
 |
 |
| Petalite |
Natural. |
N/A |
None. |
 |
 |
| Pezzottaite |
Natural. |
N/A |
None. |
 |
 |
| Phenakite |
Natural. |
N/A |
None. |
 |
 |
| Prehnite |
Natural. |
N/A |
None. |
 |
 |
| Quartz (excluding Blue Moon, Graffiti, Medusa, Phantom, Rose,
Rutile and Strawberry) |
Heated, irradiated or PVD coated. |
Occasionally used to improve colour or produce unique colours.
Physical Vapour Deposition (PVD) is an oxide enhancement that uses
optical interference to produce a variety of colours by applying a
bonded layer of fine titanium atoms to a gemstone (U.S. Patent Number
5,853,826 for Azotic Coating Technologies Inc.). |
Do not re-cut or re-polish gemstones with superficial colour (or
phenomena) surface layers. |
 |
 |
| Quartz (Blue Moon and Lavender) |
Heated. |
Usually applied to provide/improve colour and appearance. |
None. |
 |
 |
| Quartz (including Cat’s Eye Rutile, Dendritic, Graffiti, Medusa, Phantom, Rose, Rutile, Strawberry and Tourmalinated) |
Natural. |
N/A |
None. |
 |
 |
| Quartzite |
Dyed and/or impregnated with colourless plastic or hardened resin.
|
Occasionally used to improve appearance. |
None. |
 |
 |
| Rhodochrosite |
Natural. |
N/A |
None. |
 |
 |
| Rhodonite |
Dyed. |
Occasionally used for colour uniformity. |
None. |
 |
 |
| Ruby (including Mozambique, Mozambique Cat's Eye, Mozambique Star
and Star) |
Heated with a high refractive index lead-glass to fill fractures and
cavities and/or bulk diffused with certain additives (beryllium). |
Always applied to improve clarity and/or intensify colour and/or
colour uniformity and/or appearance. The lead-glass is usually yellow to
orange and artificially augments the red colour of these gems as well as
potentially adding weight. |
These gems have fillers in voids/cavities, fissures and/or open
fractures that can scratch more easily than the gem itself as well as
being more vulnerable to damage from heat or some solvents. |
 |
 |
| Ruby (AAA Tanzanian) |
Heated and/or the healing of fissures and/or filled open fractures
and cavities and/or bulk diffusion of certain additives (beryllium).
|
Usually applied to produce, intensify or lighten colour and/or
improve colour uniformity and/or appearance. |
These gems may have fillers in voids/cavities, fissures and/or open
fractures that can scratch more easily than the gem itself as well as
being more vulnerable to damage from heat or some solvents. |
 |
 |
| Ruby in Zoisite |
Natural. |
N/A |
None. |
 |
 |
| Sapphire (Black Star) |
Natural. |
N/A |
None. |
 |
 |
| Sapphire (including Blue, Ceylon, Colour Change, Fancy, Green,
Kanchanaburi, Midnight Blue, Orange, Padparadscha Colour, Pink, Purple,
Rainbow, Star, Sunset, White and Yellow) |
Heated and/or the healing of fissures and/or filled open fractures
and cavities and/or bulk diffusion of certain additives (beryllium).
|
Usually applied to produce, intensify or lighten colour and/or
improve colour uniformity and/or appearance. |
These gems may have fillers in voids/cavities, fissures and/or open
fractures that can scratch more easily than the gem itself as well as
being more vulnerable to damage from heat or some solvents. |
 |
 |
| Sapphire (AAA Ceylon, AAA Tanzanian and Padparadscha) |
Heated. |
Usually applied to produce, intensify or lighten colour and/or improve colour uniformity and/or appearance. |
None. |
 |
 |
| Sard |
Dyed or heated. |
Dying is occasional, while heating is usual. All provide colour.
|
None. |
 |
 |
| Sardonyx |
Dyed. |
Usually applied to improve colour. |
None. |
 |
 |
| Scapolite (including Cat's Eye) |
Natural. |
N/A |
Do not wear or leave for extended periods in strong light as these gems
may fade or revert to their original colour. |
 |
 |
| Scheelite |
Natural. |
N/A |
None. |
 |
 |
| Shell (Pink) |
Dyed. |
Often used to improve colour. |
Do not wear or leave for extended periods in strong light as these gems
may fade or revert to their original colour. |
 |
 |
| Sillimanite (including Cat's Eye and Star) |
Natural. |
N/A |
None. |
 |
 |
| Sodalite |
Dyed. |
Rarely used to improve colour. |
Do not wear or leave for extended periods in strong light as these gems
may fade or revert to their original colour. |
 |
 |
| Spectrolite |
Surface colourless waxing. |
Occasionally used to improve appearance. |
None. |
 |
 |
| Sphalerite |
Natural. |
N/A |
Handle with care, very fragile. |
 |
 |
| Sphene (including Capelinha) |
Natural. |
N/A |
None. |
 |
 |
| Spinel (including Black, Blue, Cobalt Blue, Fancy, Noble Red, Pink and Purple) |
Natural. |
N/A |
None. |
 |
 |
| Sugilite |
Natural. |
N/A |
None. |
 |
 |
| Sunstone (including Star) |
Natural. |
N/A |
None. |
 |
 |
| Tanzanite (including AAA) |
Heated. |
Usually applied to produce and/or improve colour. |
Can be damaged by thermal shock, do not expose to extreme temperature
changes. |
 |
 |
| Tanzanite (Bi Colour, Cat's Eye, Green, Orange, Pink and Yellow) |
Natural. |
N/A |
Can be damaged by thermal shock, do not expose to extreme temperature changes. |
 |
 |
| Tiger's Eye |
Dyed, bleached or heated. |
Commonly used to improve colour. |
Do not wear or leave for extended periods in strong light as these gems
may fade or revert to their original colour. |
 |
 |
| Topaz (AAA Imperial, Imperial and White) |
Natural. |
N/A |
None. |
 |
 |
| Topaz (excluding AAA Imperial, Imperial and White) |
Irradiated, heated, PVD coated and/or diffused. |
Usually applied to improve colour intensity or to produce unique
colours. Physical Vapour Deposition (PVD) is an oxide enhancement that
uses optical interference to produce a variety of colours by applying a
bonded layer of fine titanium atoms to a gemstone (U.S. Patent Number
5,853,826 for Azotic Coating Technologies Inc.). |
Do not wear or leave for extended periods in strong light as these
gems may fade or revert to their original colour. Do not re-cut or
re-polish gemstones with superficial colour (or phenomena) surface
layers. |
 |
 |
| Tourmaline (Bi Colour, Black, Cat's Eye, Cat's Eye Pirineu, Chrome, Kunar Valley, Mint, Pink Cuprian and Pirineu) |
Natural. |
N/A |
None. |
 |
 |
| Tourmaline (including Blue Green, Brazilian Rubellite, Cuprian,
Fancy, Green, Indicolite, Paraíba, Pink and Rubellite) |
Natural or heated and/or irradiated. |
Commonly used to improve colour intensity and appearance. |
None. |
 |
 |
| Tourmaline (Itatiaia, Mutuca Indicolite, Oyo and Santa Rosa) |
Heated. |
Commonly used to improve colour intensity and appearance. |
None. |
 |
 |
| Tourmaline (Shimoyo Rubellite) |
Natural or irradiated. |
While the vast majority of Shimoyo Rubellite is natural,
approximately 10 percent has been irradiated to improve their colour.
Please note that irradiated Tourmaline is almost impossible to detect
and is therefore generally regarded as not impacting value. |
None. |
 |
 |
| Turquoise |
Impregnated with plastic and/or surface colourless waxing and/or dyed.
|
Dying is rare, while impregnation with plastic and surface colourless
waxing is common. All improve stability, durability, lustre and/or colour.
|
None. |
 |
 |
| Unakite |
Natural. |
N/A |
None. |
 |
 |
| Zircon (including Cinnamon, Kaduna, Ratanakiri, Red, Yellow and White) |
Heated. |
Always used to improve colour. |
Do not wear or leave for extended periods in strong light as these gems may fade or revert to their original colour. |
 |
 |
| Zircon (including Brown, Green and Saffron) |
Natural. |
N/A |
Do not wear or leave for extended periods in strong light as these gems may fade or revert to their original colour. |
 |
 |
| Zultanite (including Cat's Eye) |
Natural. |
N/A |
Can be damaged by thermal shock, do not expose to extreme temperature changes. |
 |
 |