Mineral group · Apophyllite group
Apophyllite
KCa4(Si8O20)(F,OH)·8H2O
Apophyllite (usually fluorapophyllite-(K)) is the colourless, white or green tetragonal mineral with a pearly basal face that fills Deccan Trap cavities around Pune and Jalgaon with stilbite, and the green crystals of Poona are a modern classic. It is not a zeolite though it occurs with them. Indian apophyllite is among the cheapest attractive crystal groups in the trade.
| Formula | KCa4(Si8O20)(F,OH)·8H2O |
|---|---|
| IMA status | group |
| Crystal system | Tetragonal |
| Mohs hardness | 4.5–5 |
| Group | Apophyllite group |
| Type locality | None |
| Streak | White |
| Specific gravity | 2.35 |
Fakes and treatments
Some Indian groups are assembled from pieces; look for glue and matrix mismatches.
Elsewhere
Cite this article
Stratum Strata. "Apophyllite" (Mineral). Stratum Strata pack 2026.09, as of 2026-09-21. https://stratum.black/strata/minerals/apophyllite. Accessed 2026-09-21.
@misc{stratum-apophyllite,
title = {Apophyllite},
author = {{Stratum Strata}},
howpublished = {\url{https://stratum.black/strata/minerals/apophyllite}},
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.