Pyrite
Species
Common · FeS₂
Iron sulfide that often crystallises in sharp cubes and pyritohedra. Its metallic yellow surface mimics gold closely enough to deceive prospectors for centuries. In damp air it breaks down into iron sulfates and sulfuric acid, which can destroy specimens in a collection.
Identity
- Formula
- FeS₂
- Chemical class
- Sulfide
- Also known as
- Fool's gold, Iron pyrite
- Used in alchemy
- Fool's Gold Dust
Crystallography
- Crystal system
- Cubic
- Habits
- Cubic, Octahedral, Dodecahedral, Massive
- Fracture
- Conchoidal
Physical properties
- Mohs hardness
- 6.5
- Density
- 5.02 g/cm³
- Luster
- Metallic
- Colors
- metallic yellow, brass-yellow, pale brass-yellow
- Streak
- greenish black
- Transparency
- Opaque
Geology
- Origins
- Hydrothermal, Sedimentary, Metamorphic, Igneous
- Host rocks
- Granite, Sandstone, shale and clay
- Associated minerals
- Quartz, Calcite, Chalcopyrite, Sphalerite, Galena, Marcasite
- Found in
- Coal, Lapis Lazuli, Coal seam, Porphyry copper deposit, Volcanogenic massive sulfide deposit
- Geography
- worldwide
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.
- Pyrite. Mindat.org (Hudson Institute of Mineralogy).
- J. W. Anthony, R. A. Bideaux, K. W. Bladh, M. C. Nichols, Pyrite. Mineral Data Publishing, Handbook of Mineralogy, 2001.
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