Faustite: Gemstone Information
Faustite ((Zn,Cu)Al6(PO4)4(OH)84H2O) is a zinc-rich member of the turquoise group and crystallizes in the triclinic system, occurring as masses or nodules in argillized shales associated with copper mineralization. Gem materials of apple-green and yellow-green colour have been described. Light bluish green massive samples of turquoise-faustite aggregates occur at the turquoise deposit of Neyschabour, Iran. The hardness is about 4.5. The SG is near 2.9 and the RI about 1.612. The colour is caused by the copper of the turquoise content.