| Coccinite | |
|---|---|
 Coccinite, from Backofen Mine, Rhineland-Palatinate, Germany | |
| General | |
| Category | Halide mineral |
| Formula (repeating unit) | HgI2 |
| IMA symbol | Cci[1] |
| Strunz classification | 3.AB.10 |
| Crystal system | Tetragonal |
| Crystal class | Ditetragonal dipyramidal (4/mmm) H-M symbol: (4/m 2/m 2/m) |
| Space group | P42/nmc |
| Unit cell | a = 4.376 Å, c = 12.41 Å, Z = 2 |
| Identification | |
| Colour | Orange-red |
| Cleavage | Good on {001} |
| Mohs scale hardness | 2 |
| Streak | Orange |
| Diaphaneity | Translucent |
| Specific gravity | 3.17 (calculated) |
| Optical properties | Uniaxial (-) |
| Refractive index | 2.684 (avg) |
| Birefringence | 0.193 |
| Other characteristics | Volatile at room temperature, toxic |
| References | [2][3][4] |
Coccinite is a rare mercury iodide mineral with chemical formula of HgI2, mercury(II) iodide.[5][6] It was first discovered in Casas Viejas, Mexico;[7] it has also been reported from Broken Hill, New South Wales, and from a uranium mine in Thuringia and old mercury workings in the Rhineland-Palatinate in Germany.[2] At the Thuringia deposit the mineral occurs as a sublimation product resulting from fires associated with pyrite-bearing graptolitic slate.[6]
- ^ 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.
- ^ a b Coccinite on Mindat.org
- ^ Coccinite data on Webmin
- ^ Coccinite on Mineral Atlas
- ^ Witzke, T. (1997). "New data on the mercury iodide mineral coccinite, HgI2". Neues Jahrbuch für Mineralogie - Monatshefte. 1997 (11): 505–510. doi:10.1127/njmm/1997/1997/505.
- ^ a b Jambor, John; Pertsev, Nicolai; Roberts, Andrew (1998). "New Mineral Names" (PDF). American Mineralogist. 83: 907–910.
- ^ "Coccinite". Msrblog. 2018-02-14. Retrieved 2022-02-12.