The Rare Earths: Their Occurrence, Chemistry, and Technology

by Stanley Isaac Levy

Monoclinic; habit prismatic. Often amorphous and isotropic.

G = 4·0-4·5. H = 6¹⁄₂-7. Brown and green. Double Refraction strong, +ve.

Ytterby and Fahlun, Sweden; Hitterö and Malö, Norway; Llano Co., Texas; Colorado, etc.

Geikielite.

(Mg,Fe´´)TiO₃. TiO₂ = 56·1-64·8%. Specimens rich in iron are called Picroilmenite.

Massive.

G = 4 about. H = 6. Purplish or brownish black.

Ceylon.

Gorceixite.

An alumino-phosphate of alkaline and ceria earths. Cer = 0-3%.