Analysis of Topaz Gemstones with Modern Spectroscopic Techniques

Description

Topaz is a rather common gemstone frequently used in jewelry because of its hardness and good optical properties. It can be found in many places in gem quality and holds the record for the largest gemstones on earth, e.g. the 31.000 ct El Dorado topaz. When it comes in white to yellow colors it is a rather cheap material, but special colors such as orange, pink and red are very rare and therefore highly thought after - good stones often reach several hundred € per ct and more. However, it is often not only the color but a specific location which increases the prices of gemstones and we have therefore investigated samples from the most important topaz mines to see if it is possible to differentiate between them using nondestructive methods such as Infrared or Raman microscopy. Laser Ablation icp MS was also used, which can be called minimal invasive as it produces craters in the size of 10 µm that are not visible to the unaided eye. In order to broaden the data set some specimens have also been analyzed by destructive testing, using e.g. icp MS, ATR FTIR and by analysis of common impurities [1]. In this paper we would like to present the combined data obtained from orange imperial topaz (Ouro Preto, Brazil) in comparison to orange topaz from Volodarsk Volyn, Ukraine, which can be clearly differentiated with our methods.

Period	23 Sept 2015
Event title	16 th Austrian Chemistry Days
Event type	Conference
Location	AustriaShow on map