Image: <bdi><a href="https://www.wikidata.org/wiki/Q56247090" class="extiw" title="d:Q56247090"><span title="mineral collector and dealer">Robert M. Lavinsky</span></a></bdi> (CC BY-SA 3.0)
orthorhombicrareSorosilicates (Epidote group)
Tanzanite
Ca₂Al₃(SiO₄)(Si₂O₇)O(OH)
A beautiful prismatic crystal displaying the characteristic intense blue-violet color of tanzanite, known for its strong pleochroism.
Tanzanite Physical Properties
Mohs Hardness
6.5Crystal System
orthorhombicLuster
vitreousStreak Color
whiteCleavage
perfect on {100}, good on {010}Fracture
uneven to conchoidalSpecific Gravity
3.35Colors
blue, violet, purplish-blueTransparency
transparentType Locality
Merelani Hills, Lelatema Mts, Arusha Region, TanzaniaMineral Group
Sorosilicates (Epidote group)Uses
jewelry, collectorAssociated Minerals
graphite, diopside, tremolite, quartz, calcite, pyriteRarity
rareGeological Context
Tanzanite forms in a unique geological setting within regionally metamorphosed graphitic gneisses and schists, often associated with a complex tectonic history in the Merelani Hills.
