The Rare Earths: Their Occurrence, Chemistry, and Technology

by Stanley Isaac Levy

Cubic; in small octahedra.

G = 4·95. H = 5¹⁄₂. Yellow to brown; translucent.

Tripuhy, Minas Geraes, Brazil.

Loranskite.

Tantalate of E, Zr, Fe, etc. Yttr = 10; Cer = 3; ZrO₂ = 20%.

Massive.

G = 4·6. H = 5. Black; opaque. Metallic lustre.

Finland.

Lorenzenite.

Titano-silicate of Na and Zr; TiO₂ = 35; ZrO₂ = 12%.