Kishore Bagga, secretary of our US East Coast local section, reports on a recent meeting discussing the chemistry of forensic analysis of jewellery.
Members from at least six different states came to the Princeton Club, in New York City to hear from forensic gemologist Gary L. Smith. Forensic gemologists use established forensic techniques to analyse jewellery, looking at issues such as gemstone authentication, causes of damage, alterations to jewellery, testing of alloys to date period jewellery, and detection of fraudulent antiques.
Gary learned his craft in Asia and Europe, and is a master goldsmith, specialising in the identification and authentication, as well as the repair and restoration of, antique jewellery and artefacts. His business is based in Montoursville, Pennsylvania. Even the way he was dressed befitted a gemologist, with his star ruby tie chain and ancient rings, the latter to which he referred during his presentation. Following a three course meal in the club’s elegant setting, Gary began his presentation, entitled “Forensic Gemology – Case Studies & Techniques”.
His detailed talk touched on the use of gemology’s tools to ascertain a stone’s properties, the time of mounting, damage, hallmarks, cuts, and documentation of alterations. He shared how he had acquired a number of dies, which someone had discarded at the local landfill. What a day it had been for him: a treasure trove of original Victorian dies, which could manufacture new jewellery in an antique style. Gary continued with some historical aspects of gemology, for example the derivation of terms such as ‘karat’ and ‘carat’.
He concluded by sharing some of the functions of his laboratory, which include determining the content percentage of noble metals in jewellery, using a balsite stone and a line of aqua regia, and the use of x-ray fluorescence spectrometry. There was also a discussion between Gary and Ms. Karen DeHaas, Fellow of the Gemological Association of Great Britain, who discussed the valuation of antique and period jewellery. The presentation ended with Gary inviting all to inspect some of the antique jewellery he mentioned during his presentation, including the Jewish High Priest’s ring, which is over 1000 years old and has 12 stones on the breastplate to represent the 12 tribes of Israel.
Questions to Gary from the members continued until almost the end of the evening programme. The audience were captivated by his knowledge, and did not want to leave. The members all left not only satisfied by the dinner, but also the presentation and the topic. We would like to thank Gary for a wonderful presentation.
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