Image: James St. John (CC BY 2.0)
cubiccommonSilicates
Almandine
Fe3Al2(SiO4)3
A large, dark reddish-brown to purplish-red almandine garnet crystal, approximately 7.1 cm across, exhibiting a somewhat rounded dodecahedral habit.
Almandine Physical Properties
Mohs Hardness
7Crystal System
cubicLuster
vitreousStreak Color
whiteCleavage
indistinct/noneFracture
conchoidalSpecific Gravity
4Colors
deep red, reddish-brown, purplish-redTransparency
transparent/translucent/opaqueType Locality
Madison County, North Carolina, USAMineral Group
SilicatesUses
jewelry, abrasive, collectorAssociated Minerals
quartz, mica, feldspar, staurolite, kyaniteRarity
commonGeological Context
Almandine typically forms in medium- to high-grade metamorphic rocks like mica schists, gneisses, and amphibolites, often indicating high-pressure and moderate-to-high-temperature conditions during its formation.
