Image: <bdi><a href="https://www.wikidata.org/wiki/Q108103612" class="extiw" title="d:Q108103612"><span title="Wikipedian and OpenStreetMap mapper from Cologne, Open Data activist">Raimond Spekking</span></a></bdi> (CC BY-SA 4.0)
Apophyllite
KCa4(Si8O20)(F,OH)·8H2O
This specimen features a cluster of well-formed, transparent to translucent apophyllite crystals, exhibiting a blocky to pyramidal habit and a vitreous luster. The crystals are predominantly colorless or very pale, showcasing their characteristic form.
Apophyllite Physical Properties
Mohs Hardness
4.5Crystal System
tetragonalLuster
vitreousStreak Color
whiteCleavage
perfect on {001}Fracture
unevenSpecific Gravity
2.35Colors
colorless, white, green, pink, yellowTransparency
transparentType Locality
IndiaMineral Group
PhyllosilicatesUses
collector, ornamentalAssociated Minerals
stilbite, heulandite, calcite, quartz, prehniteRarity
commonGeological Context
Apophyllite typically forms as a secondary mineral in the vesicles and cavities of basaltic volcanic rocks, often associated with zeolites. It crystallizes from hydrothermal solutions circulating through these rocks during the late stages of volcanic activity.
