Greigite
| Greigite | ||
|---|---|---|
Specific gravity 4.049 | | |
| Other characteristics | Strongly magnetic | |
| References | [2][3][4] | |
Greigite is an iron sulfide mineral with the chemical formula Fe2+Fe3+2S4. It is the sulfur equivalent of the iron oxide magnetite (Fe3O4). It was first described in 1964 for an occurrence in San Bernardino County, California, and named after the mineralogist and physical chemist Joseph W. Greig (1895–1977).[4][5]
Natural occurrence and composition
It occurs in
The mineral typically appears as microscopic (< 0.03 mm) isometric hexoctahedral crystals and as minute sooty masses. Association minerals include montmorillonite, chlorite, calcite, colemanite, veatchite, sphalerite, pyrite, marcasite, galena and dolomite.[2][3]
Common impurities include Cu, Ni, Zn, Mn, Cr, Sb and As.
Crystal structure
Greigite has the spinel structure. The crystallographic unit cell is cubic, with space group Fd3m. The S anions form a cubic close-packed lattice, and the Fe cations occupy both tetrahedral and octahedral sites.[2][8]
Magnetic and electronic properties
Like the related oxide
References
- S2CID 235729616.
- ^ ISBN 0962209708. Retrieved December 5, 2011.
- ^ a b c Greigite. Mindat.org
- ^ a b Greigite. Webmineral
- ^ Skinner, Brian J.; Erd, Richard C.; Grimaldi, Frank S. (1964). "Greigite, the thio-spinel of iron; a new mineral" (PDF). American Mineralogist. 49: 543–55.
- ^ "Armor-Plated Snail Discovered in Deep Sea". news.nationalgeographic.com. Archived from the original on November 10, 2003. Retrieved 2016-08-29.
- PMID 15236743.
- ISBN 0-521-21489-0.
- .
- S2CID 121375069.