Scorodite
Scorodite is a common hydrated iron arsenate mineral, with the chemical formula FeAsO4·2H2O. It is found in hydrothermal deposits and as a secondary mineral in gossans worldwide. Scorodite weathers to limonite.
| Scorodite | |
|---|---|
 | |
| General | |
| Category | Arsenate minerals |
| Formula (repeating unit) | FeAsO4·2H2O |
| Strunz classification | 8.CD.10 |
| Crystal system | Orthorhombic |
| Crystal class | Dipyramidal (mmm) H-M symbol: (2/m 2/m 2/m) |
| Space group | Pcab |
| Unit cell | a = 8.937 Å, b = 10.278 Å c = 9.996 Å; Z = 8 |
| Identification | |
| Color | Green, blue-green, grey, grayish-green, blue, yellow-brown, nearly colorless, violet |
| Fracture | Sub-Conchoidal |
| Mohs scale hardness | 3.5-4 |
| Luster | Sub-Adamantine, Vitreous, Resinous |
| Streak | Greenish-White |
| Diaphaneity | Translucent |
| Density | measured: 3.27 g/cm3 calculated: 3.276 g/cm3 |
| Optical properties | Biaxial (+) |
| Pleochroism | Weak |
| 2V angle | Measured: 40° to 75° Calculated: 46° to 80° |
| Dispersion | relatively strong r > v |
| References | [1] |
Scorodite was discovered in the Schwarzenberg, Saxony district, Erzgebirge, Saxony, Germany. Named from the Greek Scorodion, "garlicky". When heated it smells of garlic, which gives it the name.
References
- http://www.mindat.org/min-3595.html Mindat data
Further reading
- Palache, C., H. Berman, and C. Frondel (1951) Dana's system of mineralogy, (7th edition), v. II, pp. 763–767
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