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A Gemstone's Journey
"The sheen and colouration of precious stones
are the same today as they were thousands of
years ago and will be for thousands of years to
come. In a world of change, this permanence has
a charm of its own that was early appreciated".
George Frederick Kunz (1856-1932), The
Curious Lore of Precious Stones.
This quote by Tiffany's legendary gemmologist
and famous gemstone author, George Frederick
Kunz, remains a great source of personal
insight. I consider myself to be a 'manly man',
but like most gem professionals, exceptionally
fine gemstones make me act like a giggling
school girl! Why? There is something about
gemstones that is ingrained in our psyche. To
early humans, the mystifying beauty, rarity and
durability of gemstones were unexplainable. In a
world where people aged, flowers wilted and
sunsets disappeared, gemstones alone remain
unchanged. For them, the only logical
explanation was that they were divine, forever
linking gemstones to the spiritual. From
Buddhism to Judaism, to Christianity to Islam,
this legacy is found within all major religions.
To our ancestors, gemstones weren't simply
baubles, they meant so much more. They were
amulets and talismans that people literally
believed could influence their life.
I am not for a second promoting the esoteric
attributes of gemstones. My interest in esoteric
lore is largely historical, but along with
mythology, gemstone history and scientific
gemmology, it is critical to understanding the
cultural importance of gemstones. Gem lore gives
us incredible insight into how our ancestors
viewed gemstones and the importance they placed
upon them. Today, many people, including my
wife, continue to have ideas about the 'healing'
power of gems. While some of the 'new age'
beliefs and metaphysical properties attributed
to gems are certainly intriguing, please
remember that little scientific evidence exists
to substantiate them.
Created by forces of nature between three
billion and several tens of millions of years
ago, gemstones have had one heck of a ride.
Their journey takes them right back to the
genesis of our planet. At 4.4 billion years old,
a tiny mineral fragment of Zircon discovered in
Western Australia is the oldest known object on
earth. This is pretty impressive, considering
the earth was formed less than 150 million years
before!
Gemstones formed beneath the earth's surface in
a variety of different environments, in three
different rock types:
- Igneous rocks are formed by the cooling
and hardening of magma or molten lava (e.g.
basalt and granite).
- Metamorphic rocks are formed when
igneous, sedimentary or other metamorphic rocks
undergo a physical change due to extreme heat or
pressure.
- Sedimentary rocks are formed by the
deposition of sediment (e.g. sandstone).
The Earth, Gemstones & You
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Although I've never
chained myself to a bulldozer, I am a
bit of a tree hugger and firmly believe
in a balance between human endeavours
and the environment. Having travelled
over much of our planet, I think the
earth is awesome, and treasure
everything she provides. Like most
people in the gem business, I believe
that mining should never be at the
expense of communities, workers or the
environment. All mining should be
sustainable; protect water sources from
chemicals, debris, rubbish, silt and
biological pollutants; minimise the
destruction of flora and fauna; and
restore mined land as close as possible
to its original condition. Having
routinely spent time in mining
communities in Asia and Africa, I can
testify to the standard of living
improvements sustainable gem mining
affords. |
Even though some gems form in more than one
environment, gemstone formation is broadly
classified into four processes: molten rock and
associated fluids (e.g. Amethyst, Emerald,
Garnet, Ruby, and Sapphire); environmental
changes (e.g. Andalusite, Kyanite, Lapis Lazuli,
Tanzanite and Tiger's Eye); surface water (e.g.
Agate, Malachite, Opal and Turquoise); and
formation in the earth's mantle (e.g. Diamond
and Peridot).
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Underground fires using thermal shock to split
rocks from the 'De Re Metallica' (1556) by
Georgius Agricola
(1494 - 1555). A mining method
common in 16th-century Germany, fire setting is
still used in Madagascar |
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Alluvial gold miners in Russia's Ural Mountains
in the early 20th century. It was from deposits
like these that Demantoid, a green variety of
Garnet, was discovered
in 1855 |
During antiquity, gemstones were typically
accidentally discovered just near the surface of
the earth. Even today, prospecting for coloured
gemstones still heavily relies on observation
and chance. Compared to the intense scientific
methods employed in Diamond exploration,
prospecting for coloured gemstones is downright
primitive. Mechanisation aside, mining coloured
gemstones is essentially the same as a thousand
years ago, with perseverance, hand tools and
elbow grease remaining the key components.
A gemstone deposit is the area where gemstones
occur. A deposit is called a 'mine' after it has
been worked and one gem deposit can have many
mines. Alluvial mining is the most common form
of gemstone mining. This method extracts gems
from sedimentary deposits, also known as placer
or secondary deposits because the gems are not
found in the rock in which they formed. These
deposits are caused by the erosion of host rocks
and include the prospecting of riverbeds,
sedimentary deposits beneath the earth's surface
and marine mining. The mined earth is either
washed with water or sieved, using gravity to
extract the rough gemstones.
Rough from alluvial deposits is usually rounded,
scratched and cracked due to weathering. This is
actually beneficial, as the culling of poorer
specimens has already occurred. This typically
results in a higher percentage of gem quality
crystals in alluvial deposits than primary host
rock deposits, where gems are chipped from the
rock in which they formed or are hosted.
While they spend a long time waiting in the
ground, once discovered, most gems are mined and
transformed into jewellery within a relatively
short time. It typically takes about one to
three years from mining for a gem to be set in
jewellery and sold, but this can be just a few
months or longer than 10 years. The supply chain
in the coloured gemstone industry is long and it
is not uncommon for a gemstone to pass through
seven pairs of hands from the mine to being set
in jewellery and then sold to the consumer.
In
his book, 'Gemstones: Quality and Value, Volume
1', Yasukazu Suwa states that current annual gem
mining production is about one-thirtieth of
total past production. Considering that mined
gemstones can potentially re-enter the market
every 30 years (or so), he estimates that a
volume close to that of newly mined gems
re-enters the market every year. Saying this,
new gemstone deposits are still being discovered
(Mozambique Paraíba Tourmaline) and old deposits
can start producing again (Russian Alexandrite).
Keeping up to date with new discoveries and
current availability will help you be a clever
gem buyer. Two useful diagrams are included in
this section, one that shows the relationship
between gems and people, and another that shows
the countries in which some popular gemstones
are currently mined.
The Origin of Gemstones
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