lamproites and lamprophyres, the result of highly fluid-rich melt compositions within the deep mantle. Uses Miscellaneous The largest documented single crystal of phlogopite was found in Lacey mine, Ontario, Canada; it measured 10x4.3x4.3 m3 and weighed about 330 tonnes. Similar-sized crystals were also found in Karelia, Russia. References Deer, W.A., R.A. Howie, and J. Zussman, (1963) Rock-forming minerals, v. 3, "sheet silicates", p. 42–54 Phyllosilicates Potassium minerals Magnesium minerals Iron(II) minerals Manganese minerals Monoclinic minerals Minerals in space group 12 Mica group Luminescent minerals