The Rare Earths: Their Occurrence, Chemistry, and Technology

by Stanley Isaac Levy

Massive, amorphous.

G = 4·26-4·55. H = 5-5¹⁄₂. Velvet black.

Ilmen Mountains; Nelson Co. and Bedford Co., Virginia, U.S.A.

Tysonite.

Fluoride of E, with Th, H₂O, CO₂, etc. Cer = 69·2-70·6; ThO₂ = 0-31%.

Hexagonal; in thick prisms.

G = 6·12-6·14. H = 4¹⁄₂-5. Wax yellow; transparent to translucent.

Fahlun and Österby, Sweden; Pike’s Peak, Colorado.

Uhligite.

Titanate of Zr, Ca, Al; Ca(Zr,Ti)O₃ + Al(Ti,Al)O₃? TiO₂ = 48; ZrO₂ = 22%.