Faustite
The zinc analogue of turquoise — a triclinic hydrous zinc-aluminium phosphate named for mineralogist George Faust.
Intro adapted from Wikipedia (CC BY-SA).
Faustite is an IMA-recognized mineral species in the phosphate class, with the chemical formula ZnAl₆(PO₄)₄(OH)₈·4H₂O.
It crystallizes in the triclinic crystal system (space group P-1). It is a member of the Turquoise structural group.
Key properties: Mohs hardness 5.5; specific gravity 2.92; White to pale yellow-green streak; Waxy to dull luster.
IMA symbol Fst, grandfathered status — known before the IMA’s founding, named in 1953.
Found in argillized shales in association with copper mineralization (Copper King mine, Nevada, USA).
It is found associated with Montmorillonite, apatite, chrysocolla, azurite, malachite, cuprite, kaolinite, quartz, alunite (Copper King mine, Nevada, USA).
The mineral was named to honor Dr. George Tobias Faust (1908–1985), mineralogist and geologist, U.S. Geological Survey.