Pyrrhotite
Species
Common · Fe₁₋ₓS (x = 0 to 0.17)
Iron sulfide with a variable iron-to-sulfur ratio; the less iron it holds, the more strongly magnetic it is. The most abundant sulfide of several major nickel deposits, where the nickel itself sits in the pentlandite that grows with it. Its bronze colour distinguishes it from pyrite.
Identity
- Formula
- Fe₁₋ₓS (x = 0 to 0.17)
- Chemical class
- Sulfide
- Also known as
- Magnetic pyrite
Crystallography
- Crystal system
- Monoclinic
- Habits
- Tabular, Massive, Granular
- Fracture
- Subconchoidal
Physical properties
- Mohs hardness
- 4
- Density
- 4.6 g/cm³
- Luster
- Metallic
- Colors
- bronze, brownish yellow, brown
- Streak
- black
- Transparency
- Opaque
Geology
- Origins
- Igneous, Hydrothermal
- Host rocks
- Volcanic rock, Schist and gneiss
- Associated minerals
- Pentlandite, Chalcopyrite, Pyrite, Magnetite
- Found in
- Volcanogenic massive sulfide deposit
- Geography
- Canada, Brazil, Germany, Russia, Mexico
Classification
- Rarity
- Common
- Gem quality
- No
Sources
- M. Pasero and others, IMA Commission on New Minerals, Nomenclature and Classification, The New IMA List of Minerals, updated September 2026. International Mineralogical Association (CNMNC), 2026.
- J. W. Anthony, R. A. Bideaux, K. W. Bladh, M. C. Nichols, Pyrrhotite. Mineral Data Publishing, Handbook of Mineralogy, 2001.
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