The Probert Encyclopaedia of Rocks & Minerals

MONAZITE

Monazite has the formulae (Ca,La,Nd,Th)PO4 and a relative hardness of 6. It is the chief ore of thorium and cerium. Thorium is a radioactive element. It is concentrated in sand due to its durability and high specific gravity. Associated with other heavy minerals such as magnetite, rutile, and zircon.
Research Monazite