mineral
Tanzanite
Blue Zoisite (Ca2Al3(SiO4)3(OH))
AI-generated identification · may be incorrectHardness: 6-7 Mohs; Color: Blue-violet (Trichroic); Luster: Vitreous; Crystal System: Orthorhombic; Specific Gravity: 3.35
- Hardness
- 6-7 Mohs
- Color
- Blue-violet (Trichroic)
- Luster
- Vitreous
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Physical properties
Hardness: 6-7 Mohs; Color: Blue-violet (Trichroic); Luster: Vitreous; Crystal System: Orthorhombic; Specific Gravity: 3.35
Formation & geological history
Formed through regional metamorphism approximately 585 million years ago in the Merelani Hills of Tanzania.
Uses & applications
Primarily used as a gemstone in high-end jewelry (rings, pendants) and valued as a investment-grade collector specimen.
Geological facts
It is 1,000 times rarer than diamonds and is only found in a small 4km by 2km area in Tanzania. It was named by Tiffany & Co. in 1968.
Field identification & locations
Identify by intense pleochroism (appearing blue, violet, or burgundy from different angles) and its unique location in Merelani, Tanzania.
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Metamorphic
Sandstone (with potential mineral staining/concretions)
Arenite (SiO2 based)
sedimentary
Epidote
Epidote | Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)
metamorphic
Pegmatite with Tourmaline and Quartz
Igneous Pegmatite
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Granite
Granite (Phaneritic intrusive igneous rock)
igneous
Septarian Pebble
Septarian nodule / Concretion
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