The Rare Earths: Their Occurrence, Chemistry, and Technology

by Stanley Isaac Levy

Tetragonal. Habit prismatic.

G = 5·19-5·40. H = 4¹⁄₂-5. Orange yellow; lustrous.

See under [Thorite].

Parisite.

E₂CaF₂(CO₃)₃. Cer = 50·8-64·4; Yttr = 0-2·5%.

Hexagonal. Habit pyramidal.

G = 4·36. H = 4¹⁄₂. Yellow to red; transparent.

Muso Valley, Columbia; Montana, U.S.A.; Greenland; Norway; the Urals, etc.

Perovskite.

CaTiO₃, with traces of Fe´´. TiO₂ = 58·9%.