monazite

monazite , yellow to reddish-brown natural phosphate of the rare earths , mainly the cerium and lanthanum metals, usually with some thorium . Yttrium, calcium, iron, and silica are frequently present. Monazite sand is the crude natural material and is usually purified from other minerals before entering commerce. Monazite occurs in North Carolina, South Carolina, Idaho, Colorado, Montana, and Florida in the United States, and in Brazil, India, Australia, and South Africa. It is an important source of cerium, thorium, and other rare-earth metals and compounds.

monazite Mineral (Ce,La,Y,Th)PO₄; sp. gr. 4.9–5.4; hardness 5.0–5.5; monoclinic; clove-brown to reddish-brown to orange and green; off-white streak; resinous to waxy lustre; crystals small, short, prismatic to tabular grains, with larger crystals showing striated faces; cleavage imperfect basal {001}; found extensively as an accessory mineral in granites and pegmatites, in gneisses and carbonatites, and concentrated in alluvial sands and placers. It is used as a source of cerium, thorium, and other rare-earth metals and compounds.

phosphates Rock or deposit made up largely of inorganic phosphate, commonly calcium phosphate (e.g. the minerals apatite, autunite, monazite, pyromorphite, torbernite, turquoise, vivianite, and wavellite).