Bavenite from the Nine Mile pluton near Wausau in Marathon County, Wisconsin. Scanning electron microscope image. (Photo by Al Falster.)

Formula: Ca4Be2Al2Si9O26(OH)2 Orthorhombic


Bavenite is a rare mineral found in beryllium-rich granite pegmatites.

MARATHON COUNTY: Forms white to gray bladed to acicular crystals up to 1 cm. in diameter in quartz-bearing pockets in pegmatites of the Wausau pluton. These pegmatites are exposed in the rotten granite quarries, such as those in Sec. 19 and 20 south of Rib Mountain (Falster, 1985, 1987; Falster et al., 2000).