Pseudobrookite

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

Formula: Fe2TiO5 Orthorhombic

Description:

Pseudobrookite is a rare mineral occurring in cavities in granitic, rhyolitic, basaltic and other igneous rocks.

Marathon County: Pseudobrookite occurs in small prismatic crystals in a vein with quartz, fluorite and pyrite cutting Nine Mile granite at the Ladick Quarry near the junction of Hwy 107 th 153, west of Mosinee (Buchholz, Falster, Simmons, 2007 b and c).