Heated Sapphire

August 1998

For Your Staff:Selling Treated Gemstones

Heated Sapphire

Most sapphires are enhanced by heat to produce their kaleidoscope of colors. Here's how to tell your customers about it

Sapphires come in a vast array of colors. Most are heat-enhanced to brighten the color, change it and/or make it more saturated. Heating often dissolves unwanted inclusions. Gems courtesy of James Alger Co. Inc., Manchester, NH.

This is the third in a series of articles in Professional Jeweler showing how to explain gemstone enhancements honestly and positively. Emerald started the series in June, followed by ruby in July. Look for pearls in September.

The bright, permanent colors of sapphire sold in most jewelry stores are usually the result of heat enhancement. Controlled heating transforms somewhat dingy, uninspired sapphires into an array of dazzling colors. These attributes are the desired effect of heating sapphire, a treatment that has been done for centuries.

Disclosure of sapphire heat treatments need not be a painful process if you weave it into your sales presentation with candor and honesty. As with any other gemstone enhancement, it's best to be straightforward with your customer about sapphires' final step in becoming a jewel.

Sapphires are sometimes treated in other ways, such as dyeing, coating, surface diffusion or irradiation (ask your store's gemologist to identify to you any sapphires enhanced by these less-common treatments). In this article, we will focus on heat enhancement, by far the most common treatment.

Introducing Enhancements
Natural sapphires almost always contain fibers or needles of another mineral that form during the growth process of the sapphire crystal. In some cases the fibers impart a velvety, hazy appearance that is considered a desirable trait. But in many cases, such fibers compromise the color and/or transparency of the sapphires. Heating is sometimes performed to dissolve the fibers and make the sapphires more transparent, lighter and more colorful. Other times, heating is performed merely to deepen and enrich weak color.

Blue sapphires respond in various ways to heat. Some become pale, some become more saturated – either outcome may be desirable. If a blue sapphire is too dark, for example, heating may make it lighter and bluer. If a blue sapphire is too light, heating might deepen the color.

Pale yellow sapphires can become more intense. Some sapphires even change color when heat-treated. Pink may become orangy-pink, sometimes resulting in sapphires known to the trade as padparadscha, a highly collectible form of the gemstone. (Padparadscha is a Sinhalese term describing the beautiful pinkish/orangy hue of a lotus flower.) Natural greenish sapphires may loose the yellow component and become blue, while some blue sapphires turn greenish.

It's all in the fine tuning of the heating and cooling process.

While premiums are paid for unenhanced sapphires that can stand on their own color merits, such gems are rare in today's market. Luckily, heating technology has made many attractive sapphires available to consumers at prices that are more affordable. As an example of the differences in price, a top-quality, non-treated, 4- to 5-ct. blue sapphire may reach $2,500-$4,000 wholesale per carat – possibly more. A similar heat-treated sapphire is $2,000-$4,000. (These prices do not include your markup. Be sure to include that when quoting prices to customers.)

In special cases, natural, needle-like inclusions in a sapphire (any color) may give rise to asterism effect – star sapphires. Some star sapphires are heated and cooled in such a way as to preserve asterism while saturating the color.

Special Care Advice
With a hardness rating of 9.0 on the Mohs scale, sapphires are among the hardest of gemstones and are resistant to general wear and tear. That's why sapphires are often worn in rings or bracelets. The heat enhancement itself is not subject to change over time and requires no special attention. Most sapphires can be cleaned in an ultrasonic cleaner or with a toothbrush and warm, sudsy water. Advice for Sales Associates

  • Store policies. Learn your store's policies on how to explain heat treatment to customers and on merchandise returns.
  • Written statements. Be sure to give your customers a written statement detailing the fact the sapphire has been heat-treated to enrich its color.

Additional reading

The Heat Treatment of Ruby and Sapphireby Ted Themelis, ISBN 0-9409-6510-0. Published by Gemlab Inc., Type-egraphics Inc. USA.
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, Woodstock, VT.
GIA's Gem Reference Guide,published by the Gemological Institute of America, Carlsbad, CA.
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.

 Legal Considerations

Even though sapphire heat enhancement is considered permanent by the trade and the enhancement itself does not pose special care considerations other than normal care, it's still wise to disclose any treatment or enhancement to customers. Take into account that state consumer laws allow customers to sue if they feel you did not disclose properly or advise them about proper care and protection (in spite of the FTC Guides for the Jewelry Industry saying permanent treatments need not be disclosed). Letting customers know what their beautiful product has gone through before they buy it can avert unpleasant surprises later.

The FTC Guides 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."

– by Robert Weldon, G.G.

Copyright © 1998 by Bond Communications.


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