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 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[edit]

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