Oxygen-Isotope Analysis

Scientific analysis and understanding of emeralds and their composition is important in gemology, for a number of reasons. First, being able to clearly establish the origin of an emerald is crucial in the certification and valuation of gemstones, even more so for particularly rare or expensive gemstones. Further, since synthetic or fabricated stones are generally of a significantly lower value (due to their synthetic origins), clearly determining the natural or synthetic nature of the gemstone is equally important.

One method for determining a gemstones origin is by analysis of oxygen isotopes, pioneered by French scientist Gaston Giuliani of the Petrographic and Geochemical Research Center in Vandoeuvre-les-Nancy, France. This method, developed in 2000, uses an electron ion beam to dislodge oxygen molecules from the gemstone. By analysing the resulting ratio of oxygen isotopes, the stones origin can be clearly established- usually down to a specific mine or deposit. The process causes extremely small divots on the gemstone surface, however they are not visible and it does not affect the value of the gemstone.

The technique has already been used in the analysis of several well known gemstones where the history was doubtful or otherwise in question. For example, by analysing several of the emeralds held in the collections of museums in India, their origin could be traced to Colombia; a fact long since suspected but until recently not based in science.

The original document is available at http://www.embassyemeralds.com/tiki-index.php?page=Oxygen-Isotope%20Analysis