Lepidolite is useful as a source of lithium and rubidium, while phlogopite is usually found in impure limestone.  
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.
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.  
mica