Mineral · Barite group
Celestine
Sr(SO4)
Celestine (celestite) is strontium sulfate, the pale sky-blue crystals lining geodes from Sakoany, Madagascar, and the giant crystals of the Crystal Cave at Put-in-Bay, Ohio. Madagascan geodes are cheap and abundant; Ohio and Sicilian (with sulfur) specimens are the classics. It fades in sunlight and its cleavage makes crystals flake.
| Formula | Sr(SO4) |
|---|---|
| IMA status | grandfathered |
| Crystal system | Orthorhombic |
| Mohs hardness | 3–3.5 |
| Group | Barite group |
| Type locality | Bell's Mill, Pennsylvania, USA |
| Streak | White |
| Specific gravity | 3.96 |
| Reference list | IMA List of Minerals (RRUFF) — verify formula and status against the current list |
Elsewhere
Cite this article
Stratum Study. "Celestine" (Mineral). Stratum Study pack 2026.09, as of 2026-09-19. https://stratum.black/study/minerals/celestine. Accessed 2026-09-20.
@misc{stratum-celestine,
title = {Celestine},
author = {{Stratum Study}},
howpublished = {\url{https://stratum.black/study/minerals/celestine}},
year = {2026},
note = {Mineral article, Stratum Study pack 2026.09, as of 2026-09-19; sources: stratum, wikidata. Accessed 2026-09-20.}
} Citations carry the pack version and the article's as-of date so they resolve to the same text later. The facts themselves belong to the sources listed below; cite those for the science.