Tsavorites are named after their original location near the Tsavo National Park in Kenya. A British geologist discovered them there in the 1960s. Today, the gemstones from the garnet family are very popular as jewelry – especially bright green specimens, which owe their color to traces of vanadium and chromium. “A tsavorite is in no way inferior to a top emerald, except that it is cleaner, i.e. clearer and rarer,” summarizes Clemens Schwarzinger.
As a gemologist, the deputy director of the “Institute for Chemical Technology of Organic Materials” at the JKU specializes in researching jewelry and gemstones. For his new research project on tsavorites, he secured funding from the “Gemological Research” scholarship of the international gemologist association “Accredited Gemologist Association.”
Next year he will study how tsavorites react to exposure to ultraviolet light. Depending on their exact chemical composition, the stones glow in different colors – pink, orange or not at all.
Protection against counterfeiting
Schwarzinger plans to chemically analyse several hundred tsavorites – this involves drilling tiny holes that are invisible to the eye and taking samples. The composition can vary slightly depending on the origin. In the second step, he will examine how stones of different compositions absorb light.
“The aim is to develop a simple method of investigation to examine the origin of the stones,” explains Schwarzinger. In addition to the mining location, this also includes whether the stone has been treated, for example, to change the color to make it easier to sell. Ideally, gemstone experts should be able to use this methodology, for example, when they want to determine the unclear origin of tsavorites for a customer. Gemstone experts usually have far less equipment than Schwarzinger has in his laboratory at the JKU. “So it’s very much about consumer protection – about identifying fakes or treated stones using simple means,” explains the gemologist.
The results can also be interesting as basic research. “At some point, someone investigated why rubies fluoresce – this led to the development of lasers that often use synthetic rubies and now also synthetic garnets,” says Schwarzinger.
Source: Nachrichten
