Properties
| Category | Sulfate minerals |
|---|---|
| Formula | SrSO4 sometimes contains minor calcium and/or barium |
| Crystal system | Orthorhombic |
| Color | White, pink, pale green, pale brown, black, pale blue, reddish, greyish; colourless or lightly tinted in transmitted light |
| Crystal habit | Tabular to pyramidal crystals, also fibrous, lamellar, earthy, massive granular |
| Cleavage | Perfect on {001}, good on {210}, poor on {010} |
| Fracture | Uneven |
| Tenacity | Brittle |
| Mohs scale hardness | 3.0–3.5 |
| Luster | Vitreous, pearly on cleavages |
| Streak | white |
| Diaphaneity | Transparent to translucent |
| Specific gravity | 3.95–3.97 |
From the Wikipedia article
Celestine (the IMA-accepted name) or celestite is a mineral consisting of strontium sulfate (SrSO4). The mineral is named after its occasional delicate blue color. Celestine and the carbonate mineral strontianite are the principal sources of the element strontium, commonly used in fireworks and in various metal alloys.
Source
Source record: crystal-compendium/celestite/minerals.json. Fetched from English Wikipedia by the operator 2 October 2026.
https://en.wikipedia.org/wiki/Celestine_%28mineral%29 — revision id 1308957087. Text and properties from Wikipedia, licensed CC BY-SA 4.0.