|For Your Staff:Selling Treated Gemstones
Rubies often are heated to remove haziness and improve color. Sometimes
a glassy substance seeps into fissures, fractures and cavities during this
process. Here's how to tell customers about it
|This is eighth in a series of articles in Professional Jeweler
on how to explain gemstone enhancements honestly and positively. The series
began with emerald in June 1998.|
Whether unintended or by design, one side effect of heat-treating rubies
to embellish their color is that fissures and cavities are sometimes filled
with a glass-like substance.
Corundum, the species of mineral that produces ruby, is routinely heated
at or near the source, often in antiquated heating devices. More modern
heating units reach temperatures close to the melting point of corundum:
2050° C. Both environments may contain borax or alumina powders, thought
to even out temperatures and prevent heat-related cracks.
However, these powders fuse at high temperatures and form a type of molten
glass that permeates surface-reaching cracks or fissures. While its presence
is minuscule in fissures, it can actually gather and add weight in larger
pits or cavities. These glass-filled areas may be apparent under magnification
because ruby and glass have different refractive indexes and the glass may
have more surface scratches and undercutting because it's softer than ruby.
When you talk to your customer about ruby enhancements, you might point
out these gems have been heat-enhanced for centuries. Heating rubies can
deepen or lighten certain colors and enhance clarity (see Professional
Jeweler,July 1998, pp. 123-124). Simply explain to customers the filling
of ruby fissures as a consequence of heat treatment is also common. The
process does several things:
- It seals up surface-reaching fractures and pits that may have occurred
naturally. This diminishes the fissure's visibility and unsightly appearance.
- It enhances transparency.
In cases where the ruby's integrity, especially its weight, increased
because of glass filling, you should explain this fact to customers. It's
also important to point out the vast difference in price between untreated
rubies and those that are heated or fissure-filled. Prices for comparable
looking stones may vary tens of thousands of dollars per carat!
It's up to you to gauge your customers' needs and interests. But it's
also your responsibility to help them make the most informed decision possible.
This may mean showing non-treated rubies andtreated ones. When customers
feel they've been treated honestly and fairly, you're almost certain they'll
return in the future often when they're in a position to buy a more
expensive, non-enhanced gem.
0.92-ct. ruby is from Mong Hsu, Myanmar.
|On the right side of the same ruby's pavilion note the large area where
glass filling may have fallen out of a pit (in box). The splotch in the
circle on the left side shows a glass-like filling.|
Special Care Warnings
Rubies are among the hardest gemstones and are resistant to general wear
and tear. But in the case of rubies with large fractures or pits that have
been filled, suggest your customer clean them with a warm, sudsy cloth instead
of immersion in an ultrasonic cleaner, which can loosen the filling and
damage the appearance.
Advice for Sales Associates
Learn your store's policies on disclosure and returns concerning treated
rubies. Your store owner or manager may want to adopt a written policy for
treated gemstones of this kind that a customer can read, understand and
Gem Identification Made Easyby Antoinette Matlins, Gemstone Press,
Gemological Institute of America's Gem Reference Guide,Gemological
Institute of America, Carlsbad, CA.
American Gem Trade Association Source Directory,1997/1998 Edition
(contains the Gem Enhancement Manual),American Gem Trade Association,
AGTA Gemstone Enhancements, What Your Should Know,American Gem
Trade Association, Dallas, TX.
The Heat Treatment of Ruby and Sapphireby Ted Themelis, ISBN
0-9409-6510-0. Printed in United States of America.
Rubies & Sapphiresby Fred Ward, Gem Book Publishers, Bethesda
Ruby and Sapphireby Richard W. Hughes, RWH Publishing, Boulder,
The trade considers heat enhancement of ruby to be permanent. But glass
filling as a byproduct of that treatment isn't considered permanent. Therefore,
it's wise to explain the treatment.
If you don't know whether a ruby has been treated, it may be prudent
to send it to a lab for a report. State consumer laws allow customers to
sue if they feel a retailer didn't disclose properly or advise them about
proper care and protection. Letting them know before they buy it avoids
unpleasant surprises later.
Here is what the FTC Guidelines say about gem treatments:
"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 © 1999 by Bond Communications.