In this task you will be given a text passage from a trivia quiz. You should choose the category this question belongs to from these categories: History, Science, Social Science, Fine Arts, Literature. You can only choose one category, so if in doubt, please choose the closest match.

Glauconite is an unusual representative of this class of minerals since it has no apparent cleavage and typically occurs as pellet-like grains formed on seafloors. Lepidolite is useful as a source of lithium and rubidium, while phlogopite is usually found in impure limestone. Usually separated into light and dark colored groups, typical characteristics include perfect cleavage and splendent luster. FTP, identify this group of hydrous aluminum and potassium silicate minerals including biotite and muscovite, which usually occurs in scales or sheets.
Science