Almandine
Image: James St. John (CC BY 2.0)
Mineral NameAlmandine
Chemical FormulaFe3Al2(SiO4)3
Mohs Hardness6.5
Crystal Systemcubic
Lustervitreous
Streak Colorwhite
Cleavagenone
Fractureconchoidal
Specific Gravity4
Colorsdeep red, reddish-brown, purplish-red
Transparencytranslucent
Type LocalityNorth Creek area, New York State, USA
Mineral GroupSilicates
Usesjewelry, abrasive, collector
Associated Mineralsquartz, feldspar, mica, staurolite, kyanite
Raritycommon
Description
This image displays a large, dark reddish-brown to purplish-red almandine garnet crystal, approximately 10.5 centimeters across, exhibiting a subhedral to anhedral form.
Geological Context
Almandine typically forms in metamorphic rocks like mica schists, gneisses, and amphibolites under high-pressure and high-temperature conditions. This specimen originates from the Precambrian metamorphic terrains of New York State.
