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Sapphires: Market Effect of Origin & Treatments, Pricing & Disclosure
By: Richard B. Drucker, GG
Publisher of the GemGuide

Considering the historic and pricing hierarchy of origin, the sapphire order is as follows: 1) Kashmir; 2) Yogo; 3) Burma (unheated); 4) Sri Lanka, Madagascar and others. While conducting our research at Gemworld, we found several similar stones between 3.00 and 3.99 carats. All would be classified as fine to extra fine. The Sri Lanka and Madagascar sapphires ranged in price from $2,500-$3,500 per carat. The one for $3,500 per carat was an exceptional extra fine quality from Sri Lanka. One Burma stone was rated as fine with no enhancements, and cost $3,800 per carat. The Kashmir always stands alone. The velvety textured appearance sets it apart from the others. This stone was $28,000 per carat and weighs 3.30 carats.

This chart shows the relationship between heated sapphires and unheated.

In the evolution of sapphire treatments, we have gone from heat to surface diffusion to beryllium diffusion. Corundum treatments have advanced beyond that seen in any other gem product. These treatments create alteration of color and/or clarity at the molecular level.

With yellow sapphire, the diffusion method has now displaced other methods of treatment. It is very effective and difficult to detect. A gem dealer recently told of his current dilemma in selling yellow sapphires. His long-time supplier said he could no longer guarantee that the yellow sapphires were not beryllium treated. Since testing of every stone is not practical, the assumption he must now make is that these sapphires he is buying and selling are treated in this manner.

Beryllium treated sapphires typically sell for about $30-$100 per carat. The pinks and padparadscha colors can sell for more—up to $200 per carat. The issue with all these beryllium treated sapphires is disclosure as relatively few are disclosed outside of the American Gem Trade Association (AGTA) wholesale dealer pool. Their members are required to disclose all gem treatments on invoices. For a complete list of the dealer codes used by the AGTA, you can download a PDF. Go to agta.org/gemstones/agta-gim.pdf.

At the retail level, most sapphires are sold as “heat only.” Beryllium is still not fully understood at the retail level even though so much publicity has surrounded this topic in every trade journal. The reality is that only a small percentage of all gems sold at retail stores, TV shopping, internet, or otherwise are properly disclosed for treatments. As independent appraisers, we rarely see written disclosure statements.

As appraisers, we start with the assumption of heat. Unheated gems will require a report from a qualified laboratory before assigning a premium. Identifying beryllium may be possible but not always. If unsure, refer to a laboratory. Knowing the price may be helpful. If the price is too low for the material, chances are it has been beryllium treated.

Addendums are helpful and many appraisers will include these with their appraisal reports. On our addendum, we list the Treatment, Frequency, Stability, and Care for the various gems. Sapphire listings are as follows:

• Treatment: Heat; Frequency: Usually; Stability: Excellent; Care: Normal.
• Treatment: Beryllium diffusion; Frequency: Occasionally; Stability: Excellent; Care: Normal.

As a final statement on sapphire treatments, we have real concern over how far they have gone and continue to develop. Recalling debates of more than 20 years ago, the industry was concerned back then because milky white corundum rough known as geuda, was then heated to much higher temperatures resulting in beautiful blue sapphires. The industry wondered if we had gone too far and if these should have value. Today these are accepted as routine and we no longer discuss geuda as a problem.

Richard Drucker is President of Gemworld International, Inc. In September, 2008, Gemworld and the AGTA hosted the inaugural World of Gems Conference. Proceedings of the conference contain greater detail on topics such as presented in this article. Historical price charts are also included. For information on the World of Gems Conference book, go to www.worldofgemsconference.com. For information on the GemGuide to wholesale gem pricing, or the GemGuide Appraisal Software, go to www.gemguide.com.

Photo: Wimon Monorotkul