| Metacinnabar | |
|---|---|
 | |
| General | |
| Category | Sulfide mineral |
| Formula (repeating unit) | HgS |
| IMA symbol | Mcin[1] |
| Strunz classification | 2.CB.05a |
| Crystal system | Cubic |
| Crystal class | Hextetrahedral (43m) H-M symbol: (4 3m) |
| Space group | F43m |
| Unit cell | a = 5.8717(5) Å; Z = 4 |
| Structure | |
| Jmol (3D) | Interactive image |
| SMILES [SH+2]12[HgH2-2][SH+2]3[HgH2-2][SH+2]([HgH-2]14)[HgH-2]1[S+2]5([HgH-2]38)[Hg-2]26[SH+2]2[HgH-2]([S+2]4)[SH+2]1[HgH2-2][SH+2]3[HgH-2]2[S+2][HgH-2]([SH+2]6[HgH-2]([SH+2])[SH+2]68)[SH+2]([HgH2-2]6)[HgH-2]35 (SMILES input only shows in Preview. SMILES is used to create the Jmol 3D image.) | |
| Identification | |
| Color | Grayish black |
| Crystal habit | Massive, rarely as tetrahedral crystals, as incrustations |
| Twinning | Common as lamellae on {111} |
| Cleavage | None |
| Fracture | Subconchoidal |
| Tenacity | Brittle |
| Mohs scale hardness | 3 |
| Luster | Metallic |
| Streak | Black |
| Diaphaneity | Opaque |
| Specific gravity | 7.7–7.8 |
| References | [2][3][4] |
Metacinnabar is the cubic form of mercury sulfide (HgS). It is the high temperature form and trimorphous with cinnabar (trigonal structure) and the higher temperature hypercinnabar (hexagonal structure). It occurs with cinnabar in mercury deposits and is associated with native mercury, wurtzite, stibnite, marcasite, realgar, calcite, barite, chalcedony and hydrocarbons.[2]
It was first described in 1870 for an occurrence in the Redington mine, Knoxville, Napa County, California.[3][4]
- ^ 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 Metacinnabar in the Handbook of Mineralogy
- ^ a b Metacinnabar on Mindat.org
- ^ a b Metacinnabar data on Webmineral