Alamosite
Appearance
Alamosite | |
---|---|
![]() Transparent crystals of alamosite in the matrix of leadhillite and melanotekite | |
General | |
Category | Inosilicates |
Formula (repeating unit) | Pb12Si12O36 |
Strunz classification | 9.DO.20 |
Dana classification | 65.7.1.1 |
Crystal system | Monoclinic |
Crystal class | Prismatic (2/m) (same H-M symbol) |
Space group | P2/c |
Unit cell | a = 11.209, b = 7.041 c = 12.22 [Å]; β = 113.15°; Z = 12 |
Identification | |
Color | Colorless |
Cleavage | {010} perfect |
Mohs scale hardness | 4.5 |
Luster | Adamantine |
Streak | White |
Diaphaneity | Transparent to translucent |
Specific gravity | 6.49 |
Optical properties | Biaxial (-) |
Refractive index | nα = 1.947, nβ = 1.961, nγ = 1.968 |
Birefringence | δ = 0.021 |
2V angle | 65° (meas.) |
References | [1][2] |
Alamosite (Pb12Si12O36) is a colorless silicate mineral named after the place where it was discovered, Álamos, Sonora, Mexico. It is a rare secondary mineral occurring in the oxidized zones of lead-rich deposits. For example, the infobox picture shows its association with black leadhillite.[1]
References
- ^ a b Alamosite. Webmineral. Retrieved on 2011-10-10.
- ^ Alamosite Mineral Data. Mindat.org. Retrieved on 2011-10-10.