Outstanding sharp bronze tochilinite crystals from Cornwall Mines, Lebanon County, Pennsylvania, United States of America. — Photo: David Hospital · CC BY-SA 4.0
Tochilinite
Tochilinite is an IMA-recognized mineral species in the oxides & hydroxide class, with the chemical formula 6(Fe₀.₉S)·5[(Mg,Fe)(OH)₂].
It crystallizes in the triclinic crystal system (space group C1). It is a member of the Tochilinite structural group.
Key properties: specific gravity 2.96; Moderately metallic luster.
IMA symbol Thi, IMA status: approved, named in 1971.
Found in sulfide-rich serpentinized ultramafic bodies, where it may be of rock-forming mineral abundance; in some carbonaceous chondrite meteorites.
It is found associated with Troilite, pyrrhotite, sphalerite, calcite, lizardite (Voronezh region, Russia); pyrrhotite, forsterite, clinohumite, hydromagnesite, graphite.
In honor of Professor Mitrofan Stepanovich Tochilin (1919–1968), mineralogist and geologist, Voronezh University, Voronezh, Russia.