Home > Rock Forming Minerals – June 20 > MS1363 Sodalite

Sodalite - Sold

Sodalite is a sodium aluminum silicate mineral, commonly classified with the feldspathoids. It has cubic symmetry, and occasionally forms dodecahedral crystals when conditions permit. Thomson (1812) named the mineral for its sodium content.

This is a rather large sodalite crystal, in fact a twin of two dodecahedral crystals. The color of the twin crystal consists of splotches of white and deep blue, probably indicating where sulfur is present in the crystal structure. There is a bit of attached of crystalline marble present, confirming its origin in Kokcha Valley.