For Your Staff:Selling Treated Gems
Ruby Enhancement Education
The rich color of most rubies owes itself to heat-treatment. Here's
what you need to know when discussing this enhancement with customers
This is the second in a series of articles Professional
Jeweler is presenting on how to explain gemstone enhancements honestly,
matter-of-factly and positively. The series began in the June 1998 issue
(pp. 171-172) with a look at emeralds.Almost all rubies found in a jewelry
store have been enhanced in some way. One of the most sensible ways to explain
that fact to customers is to tell them enhancement is one of the steps taken
to make some rubies even more beautiful. Heat enhancement is considered
permanent and doesn't affect durability.
As with any other gemstone enhancement, it's best to be straightforward
with customers about rubies. Take advantage of the situation by telling
the interesting story of how and why rubies are enhanced.
Rubies are sometimes treated in other ways, such as by dyeing, surface
diffusion or coating. But in this section we will focus on heat enhancement,
by far the most common.
An unheated ruby crystal, a .74-ct heat-treated ruby and a rare, top-quality
unheated 3.77-ct ruby are courtesy of Radiance International, La Jolla,
How to Introduce Enhancements
Here are some tidbits to keep in mind when selling enhanced rubies.
- Natural rubies almost always contain fibers or needles of another mineral
that form as the ruby crystal grows. This silky-looking mineral gives the
ruby a milky or hazy appearance and suppresses the bold red we associate
with rubies. (Rubies with a lot of these needles are suitable for cutting
as star rubies.)
- Rubies have been heat-enhanced since at least the 11th century, when
an Arab scholar first described the process. The premise behind heat enhancement
is unchanged, but technological advances allow the treatment of many more
rubies and in repeatable colors.
- Heating and then slow-cooling the rubies in a controlled environment
dissolves the silky crystals, making the gem more transparent and the color
- Trained gemologists and qualified laboratories generally can determine
conclusively whether a ruby has been enhanced by heat.
- Rubies often but not always are heated together with other
minerals such as silica and borax – that turn liquid.
This liquid can penetrate minute fissures and solidify in the ruby. This
material softens the visibility of pits or fissures but occurs in such
small quantities that it adds no weight. A trained gemologist or laboratory
can confirm this treatment, which is considered permanent.
- The degree to which rubies have been enhanced affects price. Prices
can rise to $30,000 per carat wholesale for 4-ct. and larger rubies that
are not enhanced. Average prices for attractive heated rubies range from
$2,000 to $5,000 per carat. Small heated rubies in commercial qualities
can sell for under $100 per carat.
Special Care Warnings
Rubies are among the hardest gems (9.0 on the Mohs scale) and are resistant
to general wear and tear. For this reason, rubies often are used in rings,
which get more wear and tear than other types of jewelry.
The heat enhancement itself is also hardy and requires no special attention.
You can clean most rubies in an ultrasonic cleaner or with a toothbrush
and warm, sudsy water. However, rubies with a lot of inclusions or large
fissures should be treated more gingerly because a hard blow or high heat
could enlarge the fissures and make them more visible. Rubies are stable
Even though heat enhancement of ruby is considered permanent by the trade
and the enhancement poses no special care considerations, it's still wise
to disclose any enhancement to customers. As you can see from the FTC guidelines
printed in the box below, there is room for debate on telling a customer
about ruby enhancement.
If you fully explain the enhancement and proper care, you can avoid unpleasantness
later. This needn't be a painful process; simply weave the enhancement information
into your sales presentation with candor and honesty. Gentle humor also
You might even let customers look at a ruby through a microscope. Remember
how thankful you were the last time a salesperson spent quality time explaining
the nuances of a product you were buying.
Finally, always be aware of your store's written policy on telling customers
The Heat Treatment of Ruby and Sapphireby Ted Themelis,
Gemlab Inc., Typegraphics Inc. USA [ISBN 0-9409-6510-0].
The Ruby & Sapphire Buying Guideby Renee Newman, International
Jewelry Publications, Los Angeles, CA.
Ruby & Sapphireby Richard Hughes, RWH Publishing, Boulder, CO.
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 Gem Enhancement
Manual), American Gem Trade Association, Dallas, TX.
AGTA Gemstone Enhancements, What You Should Know,American Gem
Trade Association, Dallas, TX.
| The FTC Guides for the Jewelry Industry say "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."
Also take into account that state consumer laws allow legal action regardless
of what the FTC says if the consumer feels something wasn't explained properly.
Copyright © 1998 by Bond Communications.