| Xitieshanite | |
| Category: | Sulfate mineral |
| Formula: | Fe3+(SO4)Cl·6(H2O) |
| Imasymbol: | Xit[1] |
| Molweight: | 313.47 g/mol |
| Strunz: | 7.DC.20 |
| System: | Monoclinic |
| Class: | Prismatic (2/m) (same H-M symbol) |
| Symmetry: | P21/a |
| Unit Cell: | a = 14.1 Å, b = 6.9 Å c = 10.67 Å; β = 111.26°; Z = 4 |
| Color: | Green; yellow green |
| Habit: | Acicular |
| Cleavage: | Uncertain / indistinct |
| Fracture: | Conchoidal to uneven |
| Mohs: | 2.5 - 3 |
| Luster: | Vitreous |
| Refractive: | nα = 1.536 nβ = 1.570 nγ = 1.628 |
| Opticalprop: | Biaxial (-) |
| Birefringence: | 0.092 |
| Dispersion: | r > v |
| Pleochroism: | Colorless (x) to pale yellow (y) to light greenish yellow (z) |
| 2V: | Measured: 77° |
| Streak: | Yellow |
| Gravity: | 1.99 |
| Diaphaneity: | Transparent to translucent |
| 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]
Xitieshanite mainly consists of oxygen (56.14%) and iron (17.82%), but otherwise contains chlorine (11.31%), sulphur (10.23%) and hydrogen (4.50%). This mineral grown in lead-zinc mines, in the oxidation zone of it. Xitieshanite is a pleochroic mineral, which is an optical phenomenon, meaning the mineral appears as if it's changing colors depending on the axis it is being inspected at. On the X axis it appears as it's colorless, while it looks pale yellow if viewed on the Y axis, and light greenish yellow on the Z axis. It doesn't show any radioactive properties whatsoever.