For Your Staff:Selling Treated Gemstones
Heated Amethyst & Citrine
Amethyst and citrine quartz may be treated with heat to saturate,
lighten or otherwise improve the color. Here's how you can discuss it with
Amethyst and citrine are similar varieties of the quartz species. The many
shades of purple to lavender amethyst and yellow to orange citrine give
consumers a lot of choice. One source in Bolivia even produces ametrine,
which is amethyst and citrine combined in one gem.
|This is the sixth in a series of articles Professional Jeweler
is presenting on how to explain gemstone enhancements matter-of-factly and
positively. Emerald started the series in June, followed by ruby in July,
sapphires in August, pearls in September and aquamarine in October.|
Amethyst and citrine have been cherished since Biblical times; the book
of Exodusidentifies amethyst as one of the gems in the High Priest's
breastplate, for example.
Years ago, gem experts found controlled heating could alter the color
of amethyst and citrine, creating more salable and interesting shades.
Nature produces the same shades of amethyst and citrine that heat-enhancement
creates, and it's difficult to determine whether the color is natural or
heat-induced. One tell-tale sign: inclusions may expand under controlled
heat, causing minute fractures in the stone. Most gemologists agree this
is a good way to tell whether quartz has been treated. Still, it's best
to tell your customer most amethysts and citrines are heat-enhanced.
How To Introduce Treatments
Explaining to customers how this heat enhancement affects amethyst and citrine
is not difficult. Simply relate what happens:
- Very dark natural amethysts are sometimes heated to produce lighter
shades. This makes them more desirable and also allows for consistent colors
that can be matched for use in jewelry.
- Very light purple amethyst can be heated to produce citrine and, to
a lesser extent, green quartz.
- If the amethyst contains color zoning, (a color concentration that
conforms to crystallographic growth patterns), these areas have the most
dramatic color changes.
Amethyst and citrine have a hardness rating of 7 on the Mohs scale and good
toughness. The results of heat-treatment on these gems are considered stable
and permanent under most conditions, so they require no special care while
being worn. But because of the treated gems' susceptibility to heat, they
should not be steam-cleaned. Instead, use a toothbrush or soft cleaning
Also, take care to guard them from heat in the setting process.
Advice for Sales Associates
Learn your store's policies on explaining heat treatment of amethyst and
citrine to customers. If you're unsure about what to say, ask the store
manager or owner.
Also give your customer a written statement explaining that most amethysts
and citrines are heat-enhanced.
Gem Identification Made Easyby Antoinette Matlins, Gemstone Press,
GIA's Gem Reference Guide,Gemological Institute of America, Carlsbad,
AGTA Source Directory,1997/1998 Edition (contains the Gem Enhancement
Manual),AGTA, Dallas, TX.
AGTA Gemstone Enhancements, What You Should Know,AGTA, Dallas,
The trade considers the colors achieved by heat-treating amethyst and
citrine to be stable and permanent under most conditions. However, it's
best to disclose the treatment because customers could feel deceived or
claim in court they would not have bought the gem had they known it was
treated. Note that in the language of the FTC Guides for the Jewelry Industry
that follows, heating is listed among the treatments that should be disclosed.
Despite the FTC Guides' mandate, consumers can still sue under state
consumer protection laws for unfair and deceptive acts and practices if
they feel you didn't explain the treatment properly.
Here's what the FTC Guides pertaining to amethyst and citrine treatment
"It is unfair or deceptive to fail to disclose that a gemstone has
been treated in any manner that is not permanent or that creates special
care requirements, and to fail to disclose that the treatment is not permanent,
if such is the case. The following are examples of treatments that should
be disclosed because they usually are not permanent or create special care
requirements: coating, impregnation, irradiating, heating, use of nuclear
bombardment, application of colored or colorless oil or epoxy-like resins,
wax, plastic, or glass, surface diffusion, or dyeing. This disclosure may
be made at the point of sale, except that disclosure should be made in any
solicitation where the product can be purchased without viewing (e.g., direct
mail catalogs, on-line services), and in the case of televised shopping
programs, on the air. If special care requirements for a gemstone arise
because the gemstone has been treated, it is recommended that the seller
disclose the special care requirements to the purchaser."
by Robert Weldon, G.G.
Copyright © 1998 by Bond Communications.