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	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.