Apophyllite

Formula: KCa4(Si8O20)(F,OH) · 8H2O

Colour: Colourless, pale green, aquamarine, white, pink, yellow

Lustre: Vitreous, Pearly

Hardness: 4½ – 5

Specific Gravity: 2.33 – 2.37

Crystal System: Tetragonal

Member of: Apophyllite Group

Name: Apophyllite was named in 1806 by Rene Just Haüy from the Greek for “away from” (ἀπό, apo) and “leaf” (φύλλον, phyllos), in allusion to the way it exfoliates upon heating. Chemical variants were recognized in1978.

Fluorapophyllite-(K) – Hydroxyapophyllite-(K) Series.