Launch of Contributions to Gemology No.10 at ETH Zurich

Red andesine from different collection points in Tibet have been tested for authenticity. Copper-bearing red andesine from the so-called new mines in Tibet (first reported in 2010) can be discriminated from diffusion-treated counterparts using high-resolution analytical techniques and methods.
The geological process of Tibetan andesine formation involved the circulation of sulfur-rich fluids that enriched Copper in the feldspars, producing a characteristic natural chemical signature.

The authenticity protocol used in this work is based on elemental fingerprints, isotopic ratio determinations of copper and argon, and micro chemical fluid inclusion analyses.
Our measurements for hand-collected materials from the old mines (first reported in 2008) partly confirm them as authentic. Instead, most of the faceted gem quality stones in the market overlap with the chemical fingerprints of diffusion-treated andesine. The authenticity remains undeterminable unless destructive methods can be used for testing.Registered at the Library of Congress, Washington, US Library of Congress RegNo 1-627542300.