WGNHS
Wisconsin Geological and Natural History Survey

Sodalite

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Blue sodalite with white nepheline. Princess Sodalite Mine, Bancroft, Ontario, Canada. Scale is in centimeters. (Photo by W. Cordua.)

Formula: Na8Al6Si6O24Cl Isometric

Description:Sodalite is a blue to white mineral found in silica-undersaturated igneous rocks and their metamorphosed equivalents. It is never found stably together with quartz, but does occur with nepheline, cancrinite and other low-silica minerals.

MARATHON COUNTY: Sodalite is a component of the nepheline syenite of the Stettin pluton exposed west of Wausau, where it is associated with nepheline, hedenbergite, arfvedsonite, aegirine, fluorite, K feldspar, zircon and cancrinite. Some known outcrops of sodalite bearing rocks are in SE SE sec. 22 T.29N. R.6E (LaBerge and Myers, 1983) and NE sec. 31 T.29N. R.7E (Weidman, 1907b).