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 | |
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General | |
Category | Arsenate minerals |
Formula (repeating unit) | FeAsO4·2H2O |
IMA symbol | Scd[1] |
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 | [2] |
Scorodite was discovered in Schwarzenberg, Saxony, Germany. Named from the Greek Scorodion, "garlicky". When heated it smells of garlic, which gives it the name.