Zoisite
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)
Mineral NameZoisite
Chemical FormulaCa2Al3(SiO4)(Si2O7)O(OH)
Mohs Hardness6
Crystal Systemorthorhombic
Lustervitreous
Streak Colorwhite
Cleavageperfect on {010}
Fractureuneven to conchoidal
Specific Gravity3.15
Colorsyellow, yellowish-green
Transparencytransparent
Type LocalityMerelani Hills (Mererani), Lelatema Mts, Arusha Region, Tanzania
Mineral GroupSilicates
Usesjewelry, collector
Associated Mineralsquartz, feldspar, garnet, epidote
Rarityuncommon
Description
A brilliantly lustrous and intensely gemmy yellowish-green zoisite crystal, displaying prominent striations along its prismatic faces and some internal fibrous inclusions.
Geological Context
Zoisite typically forms in regionally metamorphosed rocks like schists and gneisses, and in hydrothermally altered igneous rocks. It is characteristic of medium-grade metamorphic environments.
