Properties
| Category | Tectosilicate minerals |
|---|---|
| Formula | (Na,Ca)8[(S,Cl,SO4,OH)2|(Al6Si6O24)] |
| Crystal system | Isometric |
| Color | Deep blue, azure, violet-blue, greenish blue |
| Crystal habit | Crystals occur as dodecahedra, or rarely cubes; granular, disseminated, or massive |
| Cleavage | Imperfect on {110} |
| Fracture | Uneven |
| Tenacity | Brittle |
| Mohs scale hardness | 5–5.5 |
| Luster | Vitreous |
| Diaphaneity | Translucent to opaque |
| Specific gravity | 2.38–2.45 |
From the Wikipedia article
Lazurite, old name Azure spar is a tectosilicate mineral with sulfate, sulfur and chloride with the formula (Na,Ca)8[(S,Cl,SO4,OH)2|(Al6Si6O24)]. It is a feldspathoid and a member of the sodalite group. Lazurite crystallizes in the isometric system although well‐formed crystals are rare. It is usually massive and forms the bulk of the gemstone lapis lazuli.
Source
Source record: crystal-compendium/lazurite/minerals.json. Fetched from English Wikipedia by the operator 2 October 2026.
https://en.wikipedia.org/wiki/Lazurite — revision id 1351083960. Text and properties from Wikipedia, licensed CC BY-SA 4.0.