Mineral · Phyllosilicate
Okenite
Ca10Si18O46·18H2O
Okenite is the white 'cotton ball' mineral of the Deccan Traps near Mumbai, forming fluffy balls of flexible fibres in basalt geodes. It is soft, fragile and impossible to clean, so specimens are stored in closed boxes. Beware of okenite dyed pink or blue for the tourist trade.
| Formula | Ca10Si18O46·18H2O |
|---|---|
| IMA status | grandfathered |
| Crystal system | Triclinic |
| Mohs hardness | 4.5–5 |
| Group | Phyllosilicate |
| Type locality | Disko Island, Greenland |
| Streak | White |
| Specific gravity | 2.3 |
| Reference list | IMA List of Minerals (RRUFF) — verify formula and status against the current list |
Fakes and treatments
Dyed okenite in pastel colours is common; natural okenite is white.
Elsewhere
Cite this article
Stratum Strata. "Okenite" (Mineral). Stratum Strata pack 2026.09, as of 2026-09-21. https://stratum.black/strata/minerals/okenite. Accessed 2026-09-21.
@misc{stratum-okenite,
title = {Okenite},
author = {{Stratum Strata}},
howpublished = {\url{https://stratum.black/strata/minerals/okenite}},
year = {2026},
note = {Mineral article, Stratum Strata pack 2026.09, as of 2026-09-21; sources: stratum, wikidata, commons. Accessed 2026-09-21.}
} 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.