Chamosite
Image: Didier Descouens (CC BY-SA 4.0)
Mineral NameChamosite
Chemical Formula(Fe,Mg)5Al(Si3Al)O10(OH)8
Mohs Hardness2
Crystal Systemmonoclinic
Lusterpearly
Streak Colorgreenish white
Cleavageperfect on {001}
Fractureuneven
Specific Gravity3
Colorsdark green, blackish green, white, light brown
Transparencyopaque
Type LocalityVielsalm, Stavelot Massif, Luxembourg Province, Belgium
Mineral GroupSilicates (Chlorite Group)
Usesscientific research, collector's mineral
Associated Mineralsquartz
Rarityuncommon
Description
This specimen features dark green, platy to massive aggregates of Chamosite, exhibiting a pearly to dull luster, embedded within a white to light brown granular matrix. The Chamosite forms irregular patches and veins across the host rock.
Geological Context
Chamosite is a common iron-rich chlorite found in low-grade metamorphic rocks and sedimentary iron formations, typically forming under reducing conditions. It is indicative of specific metamorphic or diagenetic environments.
