Laser Ablation as a Powerful Tool in the Analysis of Gemstones
Sprache des Vortragstitels:
8th Euro-Mediterranean Symposium on Laser-Induced Breakdown Spectroscopy 2015
Sprache des Tagungstitel:
The identification and characterization of gemstones ? gemology ? is a science that is mainly based on very simple methods that can be applied be trade people and moderately trained scientists (e.g. using specific gravity, refractive index, birefringence or microscopes). However, there are limitations when it comes to structural details or modification and imitation of gems. Modern analytical techniques enable us to look into details of the chemical structure of gemstones but there is still one aspect which needs to be taken care of: You must not destroy your client´s faceted gemstones!
This prerequisite leaves us with such methods as Infrared, Raman or X-ray fluorescence, which are all nondestructive. Laser ablation is kind of on the borderline, as the craters which are left on the stone can hardly be seen with the naked eye. On the other hand when coupled to an icp MS it is a very powerful method for the analysis of trace elements in the ppm or ppb level (depending on the element). Trace elements are often responsible for specific properties of a gemstone, such as color or fluorescence and by knowing their concentration and distribution profiles it is possible to retrieve information which is far beyond what can be found with traditional gemological tools (e.g. determination of localities.)
In this paper we present the analysis of various topazes from different localities to highlight the possibilities of Laser ablation in gemology.