orthorhombic
Tanzanite
Ca2Al3(SiO4)(Si2O7)O(OH):V
Quick Facts
Hardness
6.5
Specific Gravity
3.1
Refractive Index
1.691
Crystal Structure
orthorhombic[mmm]:{100}@1.0 + {010}@0.9 + {001}@1.2 + {110}@0.7 orthorhombic
mmm
{100} {010} {001} {110}
Physical Properties
Crystal Systemorthorhombic
Hardness (Mohs)6.5
Specific Gravity3.1
CleavagePerfect in one direction
FractureUneven to conchoidal
LustreVitreous
Optical Properties
Refractive Index1.691
Birefringence0.008-0.013
PleochroismStrong trichroic (blue, purple/violet, brown/burgundy)
Dispersion0.021
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Open in Playground orthorhombic[mmm]:{100}@1.0 + {010}@0.9 + {001}@1.2 + {110}@0.7 Related Minerals
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