Alamosite

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Alamosite
Alamosite-Leadhillite-Melanotekite-ea6a.jpg
Transparent crystals of alamosite in the matrix of leadhillite and melanotekite
General
CategoryInosilicates
Formula
(repeating unit)
Pb12Si12O36
Strunz classification9.DO.20
Dana classification65.7.1.1
Crystal systemMonoclinic
Crystal classPrismatic (2/m)
(same H-M symbol)
Space groupP2/c
Unit cella = 11.209, b = 7.041
c = 12.22 [Å]; β = 113.15°; Z = 12
Identification
ColorColorless
Cleavage{010} perfect
Mohs scale hardness4.5
LusterAdamantine
StreakWhite
DiaphaneityTransparent to translucent
Specific gravity6.49
Optical propertiesBiaxial (-)
Refractive indexnα = 1.947, nβ = 1.961, nγ = 1.968
Birefringenceδ = 0.021
2V angle65° (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.