Pyrite
The mineral pyrite,[1] or iron pyrite, is an iron sulfide with the formula FeS2. This mineral's metallic lustre and pale-to-normal, brass-yellow colour have earned it the nickname fool's gold because of its resemblance to gold.[2][3][4][5][6][7] The term pyrite may also be used for some other sulphides such as copper sulphide.
| Pyrite | |
|---|---|
 | |
| General | |
| Category | Sulphide mineral |
| Formula (repeating unit) | iron disulfide (FeS2) |
| Identification | |
| Color | Pale brass-yellow, tarnishes darker and iridescent |
| Crystal habit | Cubic |
| Crystal system | Isometric Diploidal, Space group Pa3 |
| Mohs scale hardness | 6–6.5 |
| Luster | Metallic, glistening |
| Streak | Greenish-black to brownish-black; smells of sulphur |
| Specific gravity | 4.95–5.10 |
| Solubility | Insoluble in water |
| Other characteristics | paramagnetic |
History
Pyrite is the most common sulphide mineral. In ancient Roman times, the name was applied to several types of stone that would create sparks when it was struck against steel. Pliny the Elder described one of them as being brassy, which was almost certainly a reference to what is now called pyrite.[8]
By Georgius Agricola's time, the term had become a generic term for all sulphide minerals.[9]
Pyrite is usually found associated with other sulphides or oxides in quartz veins, sedimentary rock, and metamorphic rock, as well as in coal beds and as a replacement mineral in fossils. Despite being nicknamed fool's gold, pyrite is sometimes found in association with small amounts of gold.
Pyrite Media
Pyrite under normal and polarized light
Crystal structure of pyrite. In the center of the cell a S22− pair is seen in yellow
Pyritohedron-shaped crystals from Italy
A pyrite cube (center) has dissolved away from a host rock, leaving behind trace gold
As a replacement mineral in an ammonite from France
Pyrite from Ampliación a Victoria Mine, Navajún, La Rioja, Spain
Pyrite from the Sweet Home Mine, with golden striated cubes intergrown with minor tetrahedrite, on a bed of transparent quartz needles
Pyrite*Locality: Sparta, Randolph County, Illinois, USA (Locality at mindat.org)*Size: 10.6 x 9.6 x 0.3 cm.*This remarkable form of pyrite is found in narrow seams of shale between seams of coal in the mines near Sparta, Illin
References
- ↑ The name pyrite is derived from the Greek πυρίτης (puritēs), "of fire" or "in fire", from πύρ (pur), "fire".
- ↑ Julia A. Jackson, James Mehl and Klaus Neuendorf, Glossary of Geology, American Geological Institute (2005) p82.
- ↑ Albert H. Fay, A glossary of the mining and mineral industry, United States Bureau of Mines (1920) pp. 103–104.
- ↑ Hurlbut, Cornelius S.; Klein, Cornelis 1985. Manual of Mineralogy. 20th ed, John Wiley and Sons, New York. 285–286 ISBN 0-471-80580-7
- ↑ Pyrite on webmineral
- ↑ Pyrite on Mindat.org
- ↑ Handbook of Mineralogy
- ↑ James Dwight Dana, Edward Salisbury Dana, Descriptive Minerology, 6th ed., Wiley, New York (1911) p86.
- ↑ Herbert Clark Hoover and Lou Henry Hoover, translators of Georgius Agricola, [De Re Metallica], The Mining Magazine, London (1912; Dover reprint, 1950); see footnote, p. 112.