Mineral · Zeolite group
Heulandite
(Ca,Na)2-3Al3(Al,Si)2Si13O36·12H2O
Heulandite (heulandite-Ca) is a zeolite forming coffin-shaped, pearly crystals in white, salmon or (from Nashik) bright red-orange in the Deccan Traps, Iceland, the Faroes and Nova Scotia's Bay of Fundy. Red heulandite from India is the collector form. It is distinguished from stilbite by its single, coffin-shaped crystals rather than sheaves.
| Formula | (Ca,Na)2-3Al3(Al,Si)2Si13O36·12H2O |
|---|---|
| IMA status | approved |
| Crystal system | Monoclinic |
| Mohs hardness | 3.5–4 |
| Group | Zeolite group |
| Type locality | None |
| Streak | White |
| Specific gravity | 2.2 |
| Reference list | IMA List of Minerals (RRUFF) — verify formula and status against the current list |
Elsewhere
Cite this article
Stratum Study. "Heulandite" (Mineral). Stratum Study pack 2026.09, as of 2026-09-19. https://stratum.black/study/minerals/heulandite. Accessed 2026-09-20.
@misc{stratum-heulandite,
title = {Heulandite},
author = {{Stratum Study}},
howpublished = {\url{https://stratum.black/study/minerals/heulandite}},
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.