Biotite

Biotite (K,Mg,Fe,Al,Si,O,H) is as cool of a representation for the first of its four elements as it is fragile. Not as fragile as other Micas, but it’s still Mica. It can be found near Pikes Peak in El Paso Co., CO, and in pegmatites found from the Unaweep Canyon to the Utah border in Mesa Co., Colorado, or in one of the 15,750 recorded localities on mindat.org in igneous and metamorphic rock, or you can get this one…