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
Specific Gravity3.15
Colorsblue-green, gray, brown, pink, green, blue
Transparencytransparent
Type LocalityAlchuri (Alchori; Aschudi), Shigar Valley, Skardu District, Baltistan, Pakistan
Mineral GroupSilicates
Usesjewelry, collector
Associated Mineralsquartz, feldspar, garnet, kyanite, calcite
Rarityuncommon
Description
This specimen is a prismatic, transparent to translucent crystal of zoisite, exhibiting a distinct blue-green color with some internal fractures and striations.
Geological Context
Zoisite typically forms in regionally metamorphosed rocks like schists and gneisses, and in hydrothermally altered igneous rocks, often associated with medium-grade metamorphic environments.
