Читать книгу The Rare Earths: Their Occurrence, Chemistry, and Technology - Stanley Isaac Levy - Страница 111
Pyrochlore.
ОглавлениеA columbate of Ca and E, with Th, Fe, Ti, F, etc. E₂O₃ → 18; TiO₂ = 5-14%.
Cubic.
G = 4·2-4·36. H = 5-51⁄2. Dark brown.
Scandinavia; the Urals; Tasmania, etc.