| Pearcbuteite | |
|---|---|
 Pearceite from Butte, Montana, US | |
| General | |
| Category | Mineral |
| Formula (repeating unit) | Cu(Ag,Cu)6Ag9As2S11[1] |
| IMA symbol | Pea[2] |
| Strunz classification | 2.GB.15 (10 ed) 2/E.05-20 (8 ed) |
| Dana classification | 3.1.8.1 |
| Crystal system | Monoclinic or trigonal |
| Space group | P3m1 (no. 164) |
| Identification | |
| Formula mass | 2,096.80 g/mol |
| Color | Black |
| Crystal habit | Pseudohexagonal prisms |
| Cleavage | {001} Poor[3] |
| Fracture | Conchoidal to irregular |
| Tenacity | Brittle |
| Mohs scale hardness | 3 |
| Luster | Metallic |
| Streak | Black |
| Diaphaneity | Opaque |
| Specific gravity | 6.15 |
| Optical properties | Biaxial |
| Refractive index | 2.7 |
| Birefringence | 2.7 |
| Pleochroism | RL Pleochroism (in reflected plane polarised light): Very weak in air, fair in oil[3][4] |
| Other characteristics | Non-fluorescent, nonmagnetic, not radioactive |
| References | [3][4][5][6] |
Pearceite is one of the four so-called "ruby silvers", pearceite Cu(Ag,Cu)6Ag9As2S11, pyrargyrite Ag3SbS3, proustite Ag3AsS3 and miargyrite AgSbS2.[6] It was discovered in 1896 and named after Dr Richard Pearce (1837–1927), a Cornish–American chemist and metallurgist from Denver, Colorado.[4]
- ^ "IMA Mineral List with Database of Mineral Properties".
- ^ 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 c Barthelmy, David (2014). "Pearceite Mineral Data". Webmineral.com. Retrieved 7 August 2022.
- ^ a b c Anthony, John W.; Bideaux, Richard A.; Bladh, Kenneth W.; Nichols, Monte C. (2005). "Pearceite" (PDF). Handbook of Mineralogy. Mineral Data Publishing. Retrieved 7 August 2022.
- ^ Gaines et al (1997) Dana’s New Mineralogy, Eighth Edition. Wiley
- ^ a b Pearceite, Mindat.org, retrieved 7 August 2022