GFCO GEM LAB currently determines geographic origin using:
The laboratory offers origin determination whenever possible when reaching a sufficient degree of confidence. Origin are available for rubies, sapphires, emeralds, spinels, opals, jadeite and demantoids. Gemstones from different mines and world locations can have overlapping characteristics to some extent - but potentially totally overlapping characteristics as characteristics of future mines are still unknown - with the consequence that an origin opinion does not represent a guarantee of origin but what is deemed a reasonable probability of such origin by the laboratory at the time it is given. Shall the origin be of great importance for the buyer, we recommend to certify the gemstones for origin with at least two laboratories.
Most origins currently identifiable by GFCO GEM LAB are the following ones:
RUBIES ORIGINS :
SAPPHIRES ORIGINS :
EMERALDS ORIGINS :