Chemical Formula: KCaSi8O20(F,OH).8H2O

Chemical Name: Potassium Calcium Silicate

Mineral Class: Phyllosilicate

Mineral Notes: The name of the mineral means "to leaf apart" in Greek. It was given because crystals tend to peel or flake apart when heated due to the loss of water. It forms as a secondary mineral in basalts. The mineral was redefined as a group name for the Fluorapophyllite, Natroapophyllite and Hydroxyapophyllite in 1978. However the extreme difficulty in individual identification means that many of these sub-species continue to be referred to under the generic name.

Description: A single, large crystal of milky-white Apophyllite on a matrix of Stilbite and Quartz. The basic shape is octahedral but the crystal is heavily distorted. There are other, partly-twinned, smaller crystals around the base. The mineral has the classic glassy luster which makes this a superb display specimen.

Location: Nassik Quarry, Poona, India.