Mineral · Amphibole group
Tremolite
Ca2Mg5Si8O22(OH)2
Tremolite is the white to grey magnesium amphibole of marbles and dolomites, forming bladed crystals at Gouverneur and Balmat (New York), Tanzania and Ontario, with a fluorescent variety ('hexagonite', pink) from New York. Fibrous tremolite is one of the six regulated asbestos minerals and contaminates some talc. Sell only well-crystallised, non-fibrous specimens.
| Formula | Ca2Mg5Si8O22(OH)2 |
|---|---|
| IMA status | approved |
| Crystal system | Monoclinic |
| Mohs hardness | 5–6 |
| Group | Amphibole group |
| Type locality | Val Tremola, Ticino, Switzerland |
| Streak | White |
| Specific gravity | 3.0 |
| Reference list | IMA List of Minerals (RRUFF) — verify formula and status against the current list |
Handling and safety
Fibrous tremolite is asbestos; keep fibrous material sealed and never work it dry.
Elsewhere
Cite this article
Stratum Study. "Tremolite" (Mineral). Stratum Study pack 2026.09, as of 2026-09-19. https://stratum.black/study/minerals/tremolite. Accessed 2026-09-20.
@misc{stratum-tremolite,
title = {Tremolite},
author = {{Stratum Study}},
howpublished = {\url{https://stratum.black/study/minerals/tremolite}},
year = {2026},
note = {Mineral article, Stratum Study pack 2026.09, as of 2026-09-19; sources: stratum, wikidata, commons. 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.