Xitieshanite | |
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General | |
Category | Sulfate mineral |
Formula (repeating unit) | Fe3+(SO4)Cl·6(H2O) |
IMA symbol | Xit[1] |
Strunz classification | 7.DC.20 |
Crystal system | Monoclinic |
Crystal class | Prismatic (2/m) (same H-M symbol) |
Space group | P21/a |
Unit cell | a = 14.1 Å, b = 6.9 Å c = 10.67 Å; β = 111.26°; Z = 4 |
Identification | |
Formula mass | 313.47 g/mol |
Color | Green; yellow green |
Crystal habit | Acicular |
Cleavage | Uncertain / indistinct |
Fracture | Conchoidal to uneven |
Mohs scale hardness | 2.5 - 3 |
Luster | Vitreous |
Streak | Yellow |
Diaphaneity | Transparent to translucent |
Specific gravity | 1.99 |
Optical properties | Biaxial (-) |
Refractive index | nα = 1.536 nβ = 1.570 nγ = 1.628 |
Birefringence | 0.092 |
Pleochroism | Colorless (x) to pale yellow (y) to light greenish yellow (z) |
2V angle | Measured: 77° |
Dispersion | r > v |
References | [2][3] |
Xitieshanite is a hydrous iron sulfate–chloride mineral with chemical formula: Fe3+(SO4)Cl·6(H2O).
It was discovered in 1983 and named for the discovery location of Xitieshan lead/zinc ore deposit in the Qinghai Province, China. It was approved by the IMA in the year of its discovery.[4] The mineral has also been reported in 2005 from acid mine drainage from a coal mine in Green Valley, Vigo County, Indiana.[5]