Cacoxenite in Quartz
Image: <a href="//commons.wikimedia.org/wiki/User:Archaeodontosaurus" title="User:Archaeodontosaurus">Didier Descouens</a> (CC BY 4.0)
Mineral NameCacoxenite in Quartz
Chemical FormulaSiO2
Mohs Hardness7
Crystal Systemtrigonal
Lustervitreous
Streak Colorwhite
Cleavagenone
Fractureconchoidal
Specific Gravity2.65
Colorsclear, smoky, reddish-brown, golden-brown
Transparencytransparent
Type LocalityMinas Gerais, Brazil
Mineral GroupSilicates
Usesjewelry, collector's item
Associated Mineralscacoxenite
Rarityuncommon
Description
A cut gemstone of clear to smoky quartz, featuring abundant fine, needle-like inclusions of reddish-brown to golden-brown cacoxenite, creating a unique visual pattern.
Geological Context
Quartz forms in various geological settings, including hydrothermal veins and pegmatites. Cacoxenite typically forms as a secondary phosphate mineral in iron-rich environments, often crystallizing within quartz during its growth in these settings.
