Mineralpedia Details for Tetraferriphlogopite
Phyllosilicate - Monoclinic - Mica group member. Ordinary (True or Common) Mica - Trioctahderal with Mg, some substitutions for of Fe3+ for silicon at the (T) positions and OH>F at (A) otherwise would be Fluorotetraferriphlogopite.
Found in ultrabasic alkaline massif of Kovdor.
Tetraferriphlogopite from Iron mine, Kovdor Massif, Kola Peninsula, Russia
Dark bronze colored pseudo-hexagonal, prismatic crystals to 1.2cm. Member of the Mica gropu, submember - Biotite.