HONG KONG / NEW YORK: 29 September 2011 ― Ever since the lead-glass treatment of ruby/corundum hit the market nearly 10 years ago, there have been issues over how to describe and represent this material for the trade and laboratories alike. GemResearch Swisslab (GRS) and American Gemological Laboratories (AGL) have come together to begin harmonizing the description of these stones on their respective gemological reports. “We wanted to let the gemstone and jewelry industries know that GRS and AGL have begun working in a spirit of collaboration between our labs and we believe that the controversies surrounding how these stones are described on our reports is a perfect venue to demonstrate this,” indicated Dr. Adolf Peretti, President of GRS Laboratories.
“Increasingly over the past several years issues surrounding the clear representation and dis- closure of this material have come to the forefront around the world”, stated Christopher P. Smith, President of American Gemological Laboratories. “Both GRS and AGL believe that this treatment needs to be clearly distinguished on our reports from the more traditionally heated rubies that are available in the marketplace in order to avoid confusion between these two products.”
Since the lead-glass treatment of low-grade ruby/corundum began entering the market in 2003, literally hundreds of thousands of stones have been sold globally. Gemologists, gemological and trade associations, as well as laboratories around the world have extensively published, lectured and generally communicated how to recognize these stones and the inherent issues of durability that surround this treatment, as well as the need for proper disclosure.
In November 2007, AGL took a high-profile position by coining the name Composite Ruby to describe all lead-glass treated ruby/corundum, while in 2010 GRS started using the name Hybrid Ruby for the same purpose.
Several features make these stones readily recognizable by anyone with little training and a loupe or microscope. Internal characteristics such as contraction bubbles in the glass, a distinct bluish and orangey color flash and the golden to red body color of the lead-glass make these stones easy to identify without the use of a gemological laboratory or advanced analytical testing. In addition these stones are not durable. Lead-glass treated ruby/corundum may be strongly damaged by some ordinary household products and routine repair by a bench jeweler.