Monazite << MON uh zyt >> is a heavy, yellow-brown mineral. It is a compound of phosphates (phosphorus and oxygen) of the lanthanide elements and thorium. Monazite is one of the chief sources of thorium, a nuclear fuel used in some nuclear reactors. Monazite is also an important source for the lanthanide elements and compounds, used widely in glass and metal manufacturing.
Monazite occurs naturally in granite rocks and pegmatite veins. As these rocks weather and break up, the monazite settles in deposits in riverbeds and beach sand. Commercial supplies of monazite are taken from sand. The monazite is usually separated from other collected minerals by an electromagnetic process. The most important monazite deposits occur in India and Brazil. Other monazite deposits are found in the United States, Australia, Sri Lanka, Malaysia, Indonesia, Canada, and South Africa.
