Mica is a group of naturally occurring minerals that are composed of silicate sheets. TALC, the four letter solution, is a soft mineral composed of hydrated magnesium silicate. Silicate, the eight letter solution, is a compound containing silicon and oxygen. BIOTITE, the seven letter solution, is a common rock-forming mineral composed of iron, magnesium, aluminum, and potassium silicate. MUSCOVITE, the nine letter solution, is a type of mica composed of potassium aluminum silicate. ISINGLASS, the nine letter solution, is a type of mica composed of hydrated potassium aluminum silicate.