TROILITE
Class : Sulfides and sulfosalts
Subclass : Sulfides
Crystal system : Trigonal
Chemistry : FeS
Rarity : Rare
Troilite is a rare iron sulfide. It is essentially an extraterrestrial mineral : it is known almost exclusively in meteorites where it occurs either as rounded nodules in iron meteorites or as regular grains in chondrites. It accompanies chromite, graphite and various phosphates and silicates. Terrestrial troilite is known only in a serpentinite and in mafic stratified complexes. It was named in honor of Dominico Troili who discovered the mineral in 1766. Troilite is brownish gray in color, quickly tarnishing to bronze-brown; its appearance is reminiscent of pyrrhotite.
Main photo : Troilite from Alta Mine, Crescent City, California, USA © Rolf Luetcke
Troilite in the World
Twinning
Twinning is known but not visible to the eye.
Fakes and treatments
No fakes listed for this mineral species.
Hardness : 3.5 to 4.5
Density : 4.67 to 4.79
Fracture : Irregular to sub-conchoidal
Streak : Brown-black
TP : Opaque
RI : -
Birefringence : -
Optical character : -
Pleochroism : None
Fluorescence : None
Solubility : Acids
Magnetism : NoneRadioactivity : None