Adularia (Valencianite variety)
Image: <a href="//commons.wikimedia.org/wiki/User:Archaeodontosaurus" title="User:Archaeodontosaurus">Didier Descouens</a> (CC BY-SA 4.0)
Mineral NameAdularia (Valencianite variety)
Chemical FormulaKAlSi3O8
Mohs Hardness6
Crystal Systemmonoclinic
Lustervitreous
Streak Colorwhite
Cleavageperfect in two directions at 90 degrees
Fractureuneven
Specific Gravity2.57
Colorswhite, pale cream
Transparencytranslucent
Type LocalityValenciana Mine, Guanajuato, Mun. de Guanajuato, Guanajuato, Mexico
Mineral GroupSilicates (Feldspar Group)
Usescollector, scientific
Associated Mineralsquartz, calcite, pyrite, galena
Rarityuncommon
Description
This specimen features a dense aggregation of intergrown, bladed to tabular, white to pale cream crystals, forming a crystalline mass with a vitreous luster.
Geological Context
Adularia, a variety of orthoclase, typically forms in low-temperature hydrothermal veins, often associated with epithermal gold-silver deposits where it crystallizes from silica-rich fluids.
