Prehnite, Ca2Al(AlSi3)O10(OH)2 (Calcium Aluminum Silicate Hydroxide),  is an attractive mineral and is occassionally used for ornamental and carved stone purposes.

Description: A white matrix covered by a thick layer of light orange, highly crystalline Prehnite. Many of the crystals are stacked into finger-like aggregates. This is a very unusual and attractive form. In between are a number of perfectly cubic, transparent Apophyllite crystals. Also present are several small spherical, ball-like aggregates of Okenite. Many of these have protruding crystals which makes the aggregates resemble tiny pin-cusions. All togother a very rich combination.

Location: Malad Quarry, Mumbai, India.