biotite

/หˆbaษชษ™หŒtaษชt/

IPA: /B AY1 AH0 T AY0 T/

noun
  1. 1

    A dark brown mica; it is a mixed aluminosilicate and fluoride of potassium, magnesium and iron.

Source: https://en.wiktionary.org/wiki/biotite