We provide an origin determination on the following gem varieties/materials:

Sapphire (all colors), Ruby, Emerald
Paraiba/Paraiba-type tourmaline
Alexandrite, Demantoid Garnet
Pink to Red Spinel, Cobalt Spinel

Occasional: We provide an origin determination on the following gem varieties/materials:
Opal
Cats-Eye Chrysoberyl
Spinel (colors other than pink to red and cobalt)
Hiddenite Spodumene

There are certain gem species and varieties that are produced in single locations or from a commercially significant/gem-quality standpoint, from only very..