The Rare Earths: Their Occurrence, Chemistry, and Technology

by Stanley Isaac Levy

Monoclinic; in small prisms.

Yellow. High refraction and birefringence.

Pilandsberg, Transvaal.

Monazite.

Phosphate of E, with Th and SiO₂. Cer = 49-74; Yttr = 1-4; ThO₂ = 1-20%.

Monoclinic.

G = 4·9-5·3. H = 5-5¹⁄₂. Red to brown and yellow; translucent.

The Carolinas; Idaho; Brazil; Scandinavia, etc.

Mosandrite.

In composition identical with [Johnstrupite] (q.v.).