Quartz is one of the most common
minerals on earth and although Feldspar makes up more than 50% of the earth's
crust, Quartz is by far the most prolific gem material. Huge quantities of transparent material such
as Amethyst, Citrine, Prasiolite and Smokey Quartz are mined every year. Add to that the huge volume of translucent
and opaque Quartz varieties like Agate, Chrysoprase, etc. and you can
understand why Quartz is a staple of the gem industry. Quartz’ excellent hardness and durability
also makes it desirable.
There are Quartz mines all over
the globe, with most seeking out the more valuable varieties such as
Amethyst. The material is sorted to
separate out the finest material for cutting. In this process there are tons of reject material that is too included
or of undesirable color. Clean,
undesirable color material is often heat treated to create Citrine or
Prasiolite.
The remaining included Quartz is the focus of this article.
This included material can be valuable in a number of ways. The mineral inclusion could be rare in
itself, making it a collector's item, though most are only sought after if the
inclusions are aesthetically pleasing. For example, Rutile is a common inclusion in Quartz but is only
desirable if there is a moderate amount. Too much is ugly, not enough is just boring.
Just off the top of my head I can think of 10 types of
inclusions popular in Quartz, but there's probably twice as many. The most common are Rutile and Tourmaline.
Rutile is the thin often hairlike gold to red needles you see while Tourmaline
inclusions tend to be slightly thicker and black. Gold, Silver and Emerald are
often found in Quartz and usually mined out of it, but you will see this
material in the market as well. Pyrite
and Hematite provide a similar metallic look. Million year old water can be
found trapped in Quartz crystals, called Enhydro Quartz.
Super Seven:
One of the unique included Quartz varieties that has hit the
market in the last few years is being coined "Super Seven" touting up
to 7 mineral inclusions, including Amethyst, Lepidochrosite, Rutile, Tiger Eye
and Cocoxinite. You can imagine blending
that many different varieties of inclusions would make it hard to find good
looking sections. I sorted through
thousands of slices to find the pieces that had the most attractive
combinations of inclusions. These are fantastic for a show piece pendant with
all kinds of necklaces.
Drusy Quartz:
Another large portion of the Quartz that is unsuitable for
faceting yet still has merit is the crystal specimen. Large perfect crystals with good collector
merit are separated and sold. The rest
is sorted for drusy. Drusy is the
cluster of tiny crystals that form a sort of "carpet" of gems. These can be formed and shaped for use as
pendants and other jewelry. Drusy with
good color and/or banding is normally left natural. The less exciting clear, brown and white
drusy is often enhanced with coatings and diffusion. These coatings and surface diffusion are
stable and generally durable as long as you don't chip or grind the
surface. The result is low cost, super
bright and vibrant drusies.
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