AGTA: No Certs for Blue

By Gary Roskin, G.G., FGA, Senior Editor -- JCK Online, 2/1/2004 2:00:00 AM

Just as beryllium-treated padparadschas were making their debut in AGTA's Gemstone Alert in the winter of 2001, treated blue sapphires were flying into the United States under the labs' radar.

In what the AGTA Gem Testing Center is now calling a Gemstone Update instead of an alert, heated blue sapphires with an unusual color distribution are giving the labs a run for their money. Identifying these blue sapphires is called "a work in progress"—because gemologists haven't yet figured out how these sapphires are being treated.

"It is important to understand the preliminary status of this data and that the team working to discover the nature of the treatment procedure continues uncovering data on a daily basis," reports the AGTA update.

"Currently and until such time as these stones are fully characterized, AGTA-GTC is not issuing reports on sapphires that show the features described here. An interim letter describing the identification problem is given to clients stating that a report will be issued at a later date."

'Checking, please hold.' The update states, "In December 2002 a 15-ct. blue sapphire was submitted to the AGTA-GTC for examination. A light (pastel) blue to near colorless rim surrounded a deep blue color."

Even though the 15-ct. stone was Sri Lankan, the stone was tested for lattice diffusion of beryllium—a test usually reserved for Madagascar stones. SIMS testing revealed no beryllium.

Then, between June and September 2003, 10 more blue sapphires, ranging from 2 cts. to 17 cts., were seen by the lab.

"Following recent consultations with various dealers who have business in heated blue sapphires, 35 stones were identified," the update reports. "The number of stones observed with these characteristics now increases daily."

"Recently we have met with those who have been 'treating' and marketing these stones," writes Ken Scarratt, AGTA's lab director. "And we have gained many more samples, which are presently undergoing various forms of preparation and analysis. As more data becomes available and a clearer picture of the process gained, we shall inform the industry in the most appropriate manner."

AGTA has implemented a batch testing service to help the trade separate these unusual stones from other "normal" heat-treated blue sapphires.

For further information, contact AGTA, P.O. Box 420643, Dallas, TX 75342; (800) 972-1162, fax (214) 742-7334, e-mail: info@agta.org, www.agta.org.