Properties
| Category | Sorosilicate |
|---|---|
| Formula | Ca2Al3(SiO4)(Si2O7)O(OH) |
| Crystal system | Orthorhombic |
| Color | White, gray, greenish brown, greenish gray, pink, blue, purple |
| Crystal habit | Prismatic crystals with striations; massive to columnar |
| Cleavage | Perfect {010} imperfect {100} |
| Fracture | Uneven to conchoidal |
| Mohs scale hardness | 6 to 7 |
| Luster | Vitreous, pearly on cleavage surfaces |
| Streak | White or colorless |
| Diaphaneity | Transparent to translucent |
| Specific gravity | 3.10–3.36 |
From the Wikipedia article
Zoisite, first known as saualpite, after its type locality, is a calcium aluminum hydroxy sorosilicate. Its chemical formula is Ca2Al3(SiO4)(Si2O7)O(OH). It was formerly considered a member of the epidote group.
Source
Source record: crystal-compendium/zoisite/minerals.json. Fetched from English Wikipedia by the operator 2 October 2026.
https://en.wikipedia.org/wiki/Zoisite — revision id 1371469190. Text and properties from Wikipedia, licensed CC BY-SA 4.0.