Apophyllite and Prehnite Cluster Bombay, India SO24

Name: Apophyllite and Prehnite Cluster Crystal

Specimen Size:  Cabinet-Sized

Dimensions: 69x40x34 mm / 2.4x1.4x1.2 inches

Weight: 74 Grams / 2.6 Ounces

Origin: Mined in Bombay, India

Apophyllite is more often then not the star attraction and very popular among collectors for its fantastic crystals with their gem-like vitreous to pearly luster. Apophyllite almost always forms good crystals of two major types. The favorite crystal habit is the rectangular prism capped by a steep four sided pyramid. A doubly terminated crystal is exceptionally special. The faces of the pyramids are rotated 45 degrees with respect to the prism faces and so plunge down into the prism edges. This produces a diamond-shaped pyramidal face instead of a typical triangular pyramid face. The shape is an extraordinary example of tetragonal crystal form. Although normally colorless or white, colored examples of apophyllite are always treasured. Some crystals of apophyllite are cut as gems, but are mostly just for the collectors.

Prehnite can form prismatic, tabular, or pyramidal crystals, but usually occurs in botryoidal, reniform, stalactitic, granular, or compact habits.  It is usually green in colour, but may be white, colourless, yellow, or gray.  It has a colourless streak.  Prehnite is transparent to translucent, with a vitreous to pearly luster.  Prehnite forms in cavities in basaltic lavas.