Phyllosilicate - Monoclinic - Mica group member. End member. Ordinary (True or Common) Mica - Trioctahderal with lithium and aluminum in the (M) positions, Si and boron in the (T) positions, F>OH in the (A) position and K as the Interlayer cation.
Occurs as tabular crystals with hexagonal outline, also scaly, fine grained, white, gray, pale green, pale pink and violet. Can be fluorescent green. Typically found in alkaline syenites and their pegmatites including MSH and Ilimaussaq.
A nice specimen with colorless plates of Tainiolite.