|Mineral class||Sulphides : Pyrrhotite - pentlandite group.|
|Chemical formula||Fe1-xS (x=0-0.2)|
|Habitus||Crystals rare, often hexagonal tabular with horisontal striation. Often as grainy aggregates.|
|Cleavage||None, fracture subconchoidal to uneven.|
|Color||Brass yellow, sometimes with iridescence. Often with a brown tarnish.|
|Streak||Dark gray to black.|
|Occurance||Pyrrhotite forms in magmatic igneous deposits, especially when the rock is of basic or ultrabasic composition. It is also found in highly metamorphic rocks, in hydrothermal veins and sometimes even in pegmatites and sedimentary rocks.|
|Associates||Pyrite, galena, sphalerite and other sulfides.|
|Notes|| Magnetic. The magnetism is stronger the less
sulphur it contains.|
There exists a variant with x=0 which is nonmagnetic and is called troilite. It has been found in meteorites.
|Locations|| A very common mineral in sulphide mines.|
| To sulphides index.
|| Mineral group index.
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