Formula: Fe2Ti3O9
Description:
Pseudorutile generally forms as an alteration product of ilmenite during weathering, especially in tropical environments. It has recently been documented as a mineral formed during low-grade metamorphism.
SAUK COUNTY: Pseudorutile was found as tiny grains (50 µm across) in core drilled through the Seeley Slate in the early 1900s, near Baraboo in SE NW sec. 1 T11N R2E. The texture of the grains suggests that they grew during low-grade metamorphism of the slate. They are associated with minute grains quartz, muscovite, chlorite, apatite, pyrite, rutile, and tourmaline (Medaris and Fournelle, 2012).