Ferripyrophyllite

Ferripyrophyllite is a mineral belonging to the phyllosilicate group. Its chemical formula is Fe3+Al2(Si3Al)O10(OH)2. This mineral is a rare, iron-rich analogue of pyrophyllite, where some of the aluminum in the pyrophyllite structure is replaced by iron. The iron is typically in the ferric (Fe3+) oxidation state. It crystallizes in the monoclinic crystal system and often forms in masses or as fine-grained aggregates. Its color can range from yellowish-brown to reddish-brown, reflecting the presence of iron. Ferripyrophyllite is typically found in metamorphic rocks, particularly those that have undergone hydrothermal alteration. It is often associated with other iron-bearing minerals and clays. The mineral was first described in 1965 from samples found in Japan. Due to its rarity and specific formation conditions, ferripyrophyllite is not a commercially significant mineral. Its study is primarily of academic interest to mineralogists and geochemists.