THE SODALITE GROUP

The Sodalite Group is composed of minerals with a similar isometric structure and related chemistry. It is named for its most common member, sodalite. The sodalite group is also a group within a group. Its members are also part of a larger group called the feldspathoids. Feldspathoids are low silica igneous minerals. Similar to the zeolites, the feldspathoids and thus the sodalite group, have large openings in the crystal structure. The lower density common to the minerals of the sodalite group is evidence of the openess of their structure. The general formula for the sodalite group is (Na, Ca)8(AlSiO4)6(SO4, OH, S, Cl)2.

The following are members of the Sodalite Group of minerals:

• Hauyne (Sodium Calcium Aluminum Silicate Sulfate)
• Lazurite (Sodium Calcium Aluminum Silicate (Sulfate Sulfide Chloride))
• Nosean (Sodium Aluminum Silicate Sulfate)
• Sodalite (Sodium Aluminum Silicate Chloride)