Forensic Gemology: Geographic Origin Determinations

Dec 1

Throughout much of history in the gem trade, the geographic origin of a ruby or sapphire has been used to communicate not only the source from which the gem derived, but also a specific visual appearance or quality that was considered typical of tha… — Throughout much of history in the gem trade, the geographic origin of a ruby or sapphire has been used to communicate not only the source from which the gem derived, but also a specific visual appearance or quality that was considered typical of that area. Burma or Burma-type rubies typically exhibited a bright, vivid red color, whereas Thai or Thai-type rubies where commonly darker with a purplish color modifier. Photo by AGL.

The geographic provenance, or country of origin for colored stones has become a key driver in the value for important rubies, sapphires, emeralds, and other gems such as alexandrite. Paraiba-type tourmaline, spinel, and many more. However, did this situation develop and what are the gemological laboratories doing to secure these determinations?

This is a general overview of the history, approach, and challenges that face modern geographic origin determinations focused primarily on sapphires and/or rubies. However, the principles discussed apply to virtually any gem material where the geographic origin or provenance may be applied.

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