Wiktionary
minnesotaite
n. (context mineralogy English) An iron magnesium silicate of the talc group
Wikipedia
Minnesotaite
Minnesotaite is an iron silicate mineral with formula: (Fe,Mg)SiO(OH). It crystallizes in the triclinic crystal system and occurs as fine needles and platelets with other silicates. It is isostructural with the pyrophyllite- talc mineral group.