The Rare Earths: Their Occurrence, Chemistry, and Technology

by Stanley Isaac Levy

Cubic, in octahedra and dodecahedra.

G = 8·7-9·0. H = 5-6. Black; translucent to opaque.

Anneröd, near Moos, Norway.

Brookite.

Titanium dioxide, TiO₂ = 99-100%; trimorphous with Anatase and Rutile.

Orthorhombic.

G = 3·87-4·01. H = 5¹⁄₂-6. Brown; opaque.

Dauphiné; Urals; Switzerland; Magnet Cove, Arkansas.

Calciothorite.

A variety of Thorite containing lime—5ThSiO₄,2Ca₂SiO₄ + 10H₂O. ThO₂ = 59·3%.