An important source of thorium and cerium

• A reddish-brown mineral containing rare earth metals

Wiktionary Word definitions in Wiktionary
n. (context mineralogy English) any of a range of reddish-brown minerals that are mixed phosphates of the lighter rare earth elements lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium and yttrium

WordNet Word definitions in WordNet
n. a reddish-brown mineral containing rare earth metals; an important source of thorium and cerium

The Collaborative International Dictionary Word definitions in The Collaborative International Dictionary
Monazite \Mon"a*zite\ (m[o^]n"[.a]*z[imac]t), n. [From Gr. mona`zein to be solitary, in allusion to its isolated crystals.] (Min.) A mineral occurring usually in small isolated crystals, -- a phosphate of the cerium metals.

Wikipedia Word definitions in Wikipedia
Monazite is a reddish-brown phosphate mineral containing rare earth metals. It occurs usually in small isolated crystals . It has a hardness of 5.0 to 5.5 on the Mohs scale of mineral hardness and is relatively dense , about 4.6 to 5.7 g/cm. There are at ...