Alamosite

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Alamosite
Alamosite-Leadhillite-Melanotekite-ea6f.jpg
Transparent crystals of alamosite in the matrix of leadhillite and melanotekite
General
Category Inosilicates
Formula
(repeating unit)
Pb12Si12O36
Strunz classification 09.DO.20 09
Crystal symmetry Monoclinic – prismatic, H-M symbol (2/m), space group P2/n
Unit cell a = 11.209 Å, b = 7.041 Å, c = 12.22 Å, Z = 12; β = 113.15°
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[edit]

  1. ^ a b Alamosite. Webmineral. Retrieved on 2011-10-10.
  2. ^ Alamosite Mineral Data. Mindat.org. Retrieved on 2011-10-10.