Know Everything About Gemstone Treatments and Enhancements
Though stone
treatment has gone on for centuries, new techniques and methods are
now available and many of today’s gemstones are treated to
improve their appearance and make them more marketable. While it is
common knowledge within the gem trade that stones are enhanced
through treatment, the buying public has known little about the
treatments until recently.
As long as the
consumer realizes that the stone has been treated, and the value
adjusted accordingly, this is not a deceptive or underhanded
practice. Treatments can do such things as change or enhance color,
make the stone more durable and enhance the character of the stone.
Unless the stone is stated to be natural, we can almost always assume
that the stone has been treated with the common treatments used on
that type of gemstone. Natural
precious stones with no treatment at all are a rarity and very expensive.
Treatment
maybe as simple as the old treatment of soaking chalcedony in honey
then ageing it on the roof of the house so the honey caramelized and
changed the color. When the stone turned black, it was called Black
Onyx. Gemstones can be treated with heat, laser treatment, radiation,
bleaching, stabilization, putting in acid, applying pressure, oiling,
impregnation, dyeing, or combinations of any of these techniques.
Here are just a few examples of common stone treatments:
1. Chalcedony
is treated with heat to become Carnelian, and when it is dyed black,
we call it Black Onyx.
2. Aquamarine
is sometimes heated at a low temperature to bring out the blues and
lessen the naturally occurring yellows, which make greens appear in
the stone.
3. Rubies are
rarely available these days that have not been heat treated, but if
you can find natural rubies, the value is at least 30% better than
that of a treated stone.
4. Diamonds in
colors have become quite popular. Many of these are treated with
radiation or a combination of pressure and heat. Naturally colored
diamonds are far more valuable than their treated counterparts.
5. Emeralds
can be treated with oil or impregnated with polymers, even dyed
polymers to enhance color.
6. Tanzanite
is naturally brown and when it is treated with heat the
characteristic blue with violet undertones becomes apparent.
7. Sapphires
are sometimes heat treated at a high temperature to bring out the
dark blues and enhance the clarity of the stones.
8. The
Padparadscha Sapphire is most often treated with heat to enhance the
brilliance of the color.
9. Pearls have
been bleached, waxed, heated, dyed and irradiated to enhance their
color and luster.
10. Citrine is
frequently heat-treated amethyst or smoky quarts. Natural citrine is
usually a light yellow.
11. Topaz is
often irradiated or heated to bring out the brilliant blues. It is
also sometimes sliced and layered by color to give an almost
iridescent color. This topaz is usually called Mystic Topaz.
12. Turquoise
can be dyed, stabilized, have the matrix enhanced and even backed
with plastic when it is mounted.
If the price
of any of these stones seems too good to be true, you are probably
looking at a treated stone. If no deception is practiced and the
buyer and seller are both happy with the transaction gemstone
treatment is not an unethical or deceptive practice. |
