how do you stablize tourquoise

How is turquoise stabilized?

Why is some stabalized and some natural?

What happens if it is not stabilzed?

Thanks

Turquoise occurs in nature in several varieties. Some of it is solid and
hard and will cut and polish with very little difficulty. Some turquoise has
the consistency of chalk. And in some deposits, it will occur as both the
hard variety and the soft form and every texture in between. The soft,
porous varieties are impregnated with an epoxy or some variety of plastic to
give it hardness, bring out the color, and to enable cutting and polishing.
Thus, it is stabilized. Natural,hard, deep colored stones are relatively
rare and are expensive. Stabilized blue chalk is not rare, but can be
expensive depending on the market and the marketer. Hope this helps, Will
Estavillo
BTW, there is such a thing as turquoise crystals. They are very small but
truly beautiful.

"koulaid" wrote in message
...
How is turquoise stabilized?

Why is some stabalized and some natural?

What happens if it is not stabilzed?

Thanks

On Wed, 01 Oct 2003 21:37:07 -0700, in rec.crafts.jewelry "will e"
wrote:

Turquoise occurs in nature in several varieties. Some of it is solid and
hard and will cut and polish with very little difficulty. Some turquoise has
the consistency of chalk. And in some deposits, it will occur as both the
hard variety and the soft form and every texture in between. The soft,
porous varieties are impregnated with an epoxy or some variety of plastic to
give it hardness, bring out the color, and to enable cutting and polishing.
Thus, it is stabilized. Natural,hard, deep colored stones are relatively
rare and are expensive

Will's post covers it well, but a couple points might be worth adding.

First, when Will says "several varieties", understand that this is all still the
same mineral. What differs is the densisty of the deposit, as well as,
sometimes, the amount of silica that is co-deposited with the turqoise, which
further hardens it.

Those turqoise deposits that happen to be dense and solid, especially that with
a bit of silica already impregnating it naturally, don't need, and generally
dont benefit from treatments. The best of this material is often very costly,
and includes the types typically called Persion (which can be from anywhere,
it's a description of the quality, not a location), but also can include some of
the best types with matrix too. The color of such deposits can vary some, but
generally will be deeper and richer blues.

However, much turqoise is deposited in a less dense chalkier form, with
literally more air spaces between the crystals. These are more porous,
sometimes very much so, and as they come from the ground, can look only very
pale blue color. Such turqoise can quickly absorb various chemicals or
treating agents, and in doing so, the "wetting" action brings out the real color
of the mineral, so it then looks a nice turqoise blue. The traditional
treatment for these was to oil or wax the stones, which deepened the color. The
trouble is that some of the other things that can absorb into the turqoise,
including soaps and perspiration, and other things, can also cause some chemical
changes, turning the color of the stone from blue, to various shades of greenish
blues, or even just green. and neither oils or waxes prevent this, and may even
accelerate it. One reason the current treatments are called stabilization,
rather than just color enhancing, or hardening, is that the resin treatments
also prevent this weathering or aging to the green colors, so the color after
resin impregnation is stable over time. Several resins can be used, including
epoxies, and polyesters, and there are a few single componant chemistries used
too. You should also be aware that some of the lowest grades of chalk turqoise
are treated with resins that aren't just an honest clear color, but have dye
added too. That looks darker blue, but isn't normallyc onsidered an honest
piece of turqoise any more. Also, there are "treatments" which amount to
grinding up turqoise chalk, mixing with resins, and forming the mass into a
block, somtimes with other things to mimic "matrix", and sometimes with dye
added as well. This stuff gets called "reconstituted", and is quite common for
use in beads, or cheaper jewelry. It benefits from very even color from batch
to batch, so manufacturers of the mass market jewelry like it, but frankly, it
has more in common with glass or plastic, than turqoise the gem.

However, there is one other non-natural turqoise worth mentioning. At one point
a few decades ago, the gem synthesis pioneer Pierre Gilson figured out how to
actually grow true turqoise in the lab, just as he figured out opals, emeralds,
and a number of ther gems he synthesizes. his synthetic is NOT just a mix of
dust and resin, but is a true synthetic version of fine persion turqoise, No
the resin filler. Not natural, but a perhaps, depending on your viewpoint, a
worthy material in it's own right, and it's stable without needing treatment.

Peter Rowe.

Thanks for the detailed information. Both responses educated me.

dk