| Semseyite | |
|---|---|
 Semseyite - Brioude-Massiac (Massif Central) France (11x3.5cm)[1] | |
| General | |
| Category | Sulfosalt mineral |
| Formula (repeating unit) | Pb9 Sb 8 S21 |
| IMA symbol | Ssy[2] |
| Strunz classification | 2.HC.10d |
| Crystal system | Monoclinic |
| Crystal class | Prismatic (2/m) (same H-M symbol) |
| Space group | C2/c |
| Unit cell | a = 13.64 Å, b = 11.96 Å c = 24.46 Å; β = 105.87°; Z = 4 |
| Identification | |
| Color | Dark gray to black |
| Crystal habit | Tabular, elongated prismatic crystals, commonly twisted; rosettelike groups |
| Cleavage | Perfect on {112} |
| Tenacity | Brittle |
| Mohs scale hardness | 2.5 |
| Luster | Metallic |
| Diaphaneity | opaque |
| Specific gravity | 6.15 |
| References | [3][4][5] |
Semseyite is a rarely occurring sulfosalt mineral and is part of the class of lead antimony sulfides. It crystallizes in the monoclinic system with the chemical composition Pb9Sb8S21. The mineral forms dark gray to black aggregates.
- ^ J.J. Périchaud : "Metal Layers of the District with Antimony of Brioude-Massiac (French Massif Central)", BRGM, 1968
- ^ 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.
- ^ Handbook of Mineralogy
- ^ Mindat
- ^ Webmineral data