| Ferroselite/Dzharkenite | |
|---|---|
 Ferroselite found in Argentina | |
| General | |
| Category | Selenide mineral |
| Formula (repeating unit) | FeSe2 |
| IMA symbol | Fse[1] |
| Strunz classification | 2.EB.10a |
| Crystal system | Orthorhombic |
| Space group | Pnnm (no. 58) |
| Identification | |
| Color | Steel-gray to tin-white with a rose tint, brass yellow |
| Crystal habit | Acicular prismatic |
| Twinning | Stellate and cruciform twins common |
| Mohs scale hardness | 6 – 6.5 |
| Luster | Metallic |
| Streak | Black |
| Specific gravity | 7.20 |
| Refractive index | Opaque |
| Pleochroism | Distinct |
| Solubility | insoluble in water |
| References | [2][3][4] |
Orthorhombic ferroselite and its isometric polymorph dzharkenite are iron selenides of general formula FeSe2 precipitated under reducing conditions in anoxic environments. They are a source of selenium in the Rocky Mountains where selenium occurrence is associated with Upper Cretaceous shale deposits.
In the frame of safety assessment calculations made for deep disposal of high-level radioactive waste, ferroselite and dzharkenite are also considered in geochemical calculations as one of the mineral phases limiting the solubility of Selenium-79.[5]
- ^ Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi:10.1180/mgm.2021.43. S2CID 235729616.
- ^ Ferroselite (FeSe2) on mindat.org
- ^ Ferroselite (FeSe2) on webmineral.com
- ^ Ferroselite (FeSe2) in Handbook of Mineralogy (rruff.geo.arizona.edu)
- ^ "Marivoet et al. (2001) Safir 2 report. Ondraf/Niras" (PDF). Archived from the original (PDF) on 2011-04-30. Retrieved 2010-01-06.