Image: James St. John (CC BY 2.0)
cubicuncommonSilicates
Grossular
Ca3Al2(SiO4)3
The image displays several well-formed grossular garnet crystals, ranging in color from red and light tan to olive-green and olive-brown, with sizes between 1.4 and 2.6 centimeters across. These crystals exhibit a characteristic vitreous luster and distinct isometric forms.
Grossular Physical Properties
Mohs Hardness
7Crystal System
cubicLuster
vitreousStreak Color
whiteCleavage
noneFracture
conchoidalSpecific Gravity
3.65Colors
red, light tan, olive-green, olive-brown, colorless, yellow, orange, pinkTransparency
transparentType Locality
MexicoMineral Group
SilicatesUses
jewelry, collector, abrasivesAssociated Minerals
quartz, feldspar, diopside, calcite, vesuvianiteRarity
uncommonGeological Context
Grossular typically forms in contact metamorphic rocks, particularly in calc-silicate skarns, marbles, and serpentinites, often resulting from the metamorphism of impure limestones or dolomites.
