Chemistry:Epidote group
From HandWiki
| Epidote group | |
|---|---|
 | |
| General | |
| Category | Sorosilicates |
| Formula (repeating unit) | (A2+ 1A2+ 2)(M3+ 1M3+ 2M3+ 3)O[Si 2O 7][SiO 4](OH) |
| Crystal system | Monoclinic |
| Crystal class | Prismatic (2/m) (same H–M symbol) |
| Space group | P21/m |
| Identification | |
| Color | Yellow-green, pistachio green, greenish black, brownish-green, green, black |
| Crystal habit | Prismatic, fibrous, druse/encrustation, massive |
| Twinning | On [100] |
| Cleavage | {001} perfect and {100} imperfect |
| Mohs scale hardness | 6–7 |
| |re|er}} | Vitreous |
Epidotes are a group of sorosilicate minerals that are common in igneous and metamorphic rocks.[1][2][3]
Epidote member species
- Clinozoisite, (CaCa)(AlAlAl)O[Si
2O
7][SiO
4](OH) - Epidote, (CaCa)(AlAlFe3+)O[Si
2O
7][SiO
4](OH) - Epidote-(Sr), (CaSr)(AlAlFe3+)O[Si
2O
7][SiO
4](OH) - Hancockite, (CaPb)(AlAlFe3+)O[Si
2O
7][SiO
4](OH) - Heflikite, (CaCa)(AlAlSc)O[Si
2O
7][SiO
4](OH) - Mukhinite, (CaCa)(AlAlV3+)O[Si
2O
7][SiO
4](OH) - Niigataite, (CaSr)(AlAlAl)O[Si
2O
7][SiO
4](OH) - Piemontite, (CaCa)(AlAlMn3+)O[Si
2O
7][SiO
4](OH) - Piemontite-(Pb), (CaPb)(AlAlMn3+)O[Si
2O
7][SiO
4](OH) - Piemontite-(Sr), (CaSr)(AlAlMn3+)O[Si
2O
7][SiO
4](OH) - Tweddillite, (CaSr)(Mn3+AlMn3+)O[Si
2O
7][SiO
4](OH)
References
- ↑ Armbruster, T.; Bonazzi, P.; Akasaka, M.; Bermanec, V.; Chopin, C.; Gieré, R.; Heuss-Assbichler, S.; Liebscher, A. et al. (2006). "Recommended nomenclature of epidote-group minerals". European Journal of Mineralogy 18 (5): 551−567. doi:10.1127/0935-1221/2006/0018-0551. Bibcode: 2006EJMin..18..551A.
- ↑ Kartashov, P. M. (2014). "Classification diagram for REE-bearing members of the epidote group based on crystallochemical data". Proceedings of the Workshop on Acessory Minerals: 25−26.
- ↑ Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine 85 (3): 291–320. doi:10.1180/mgm.2021.43. Bibcode: 2021MinM...85..291W.
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