Determining authenticity and geographic provenance of gems with crystalline structure comprises comparing ratios between values determined by shining light beam onto gem with homologous ratios from authentic gems

摘要

A light beam (4) is shone onto the gem (2) and values (A10, A12, A14 ...) are determined linked to the absorbancy of the gem for beam wavelengths in a direction of absorption set relative to a characteristic axis (c-c) of the crystal. At least one ratio (r1, r2, r3) between the values is calculated and each ratio is compared with homologous ratios from authentic gems of known provenance.