Troilite | |
Chemical Formula |
FeS |
Species |
Sulfides |
Crystal System |
Hexagonal |
Mohs Scale |
3-4 |
Specific Gravity |
4.67-4.79 |
Color |
Pale gray brown |
Streak |
Gray black |
Luster |
Metallic |
Diaphaneity |
Opaque |
Cleavage |
None Observed |
Fracture |
Irregular |
Crystal Habit:Massive, granular; nodular; platey to tabular | |
Geological Setting:Troilite occurs in serpentine, in layered ultramafic intrusives, and in meteorites. Known terrestial occurrences of troilite are not common. Found in a great number of meteorites (also Lunar and Martian) and in planetary nebulae. Found in slags and also in pulverized coal particles after combustion. Based on observations by the Voyager spacecraft in 1979 and Galileo in 1996, troilite seems to be an important phase in the mineral composition of the model rock of Jupiter's Galilean satellites Ganymede and Callisto. Based on the observations of Viking-1 and Viking-2-XRF-soil analyses and Phobos-2 orbital γ-ray data, troilite is likely to be a common mineral in the Martian surface rocks. |