Fluorapophyllite-(K)
Image: <a href="//commons.wikimedia.org/wiki/User:Archaeodontosaurus" title="User:Archaeodontosaurus">Didier Descouens</a> (CC BY-SA 4.0)
Mineral NameFluorapophyllite-(K)
Chemical FormulaKCa₄(Si₈O₂₀)F·8H₂O
Mohs Hardness4.5
Crystal Systemtetragonal
Lustervitreous
Streak Colorwhite
Cleavageperfect on {001}
Fractureuneven
Specific Gravity2.37
Colorspale yellow, greenish-yellow, colorless, white
Transparencytransparent
Type LocalityKorsnäs, Vaasa, Länsi-Suomen Lääni, Finland
Mineral Groupphyllosilicates
Usescollector, ornamental
Associated Mineralszeolites, calcite, quartz, prehnite
Rarityuncommon
Description
The image displays a cluster of small, pale yellowish-green, transparent to translucent Fluorapophyllite-(K) crystals forming a druse, nestled within a cavity alongside larger, more opaque, light brown/tan mineral formations.
Geological Context
Fluorapophyllite-(K) typically forms as a secondary mineral in the vesicles and cavities of basaltic and other volcanic rocks, as well as in granitic pegmatites and some metamorphic environments.
