Читать книгу The Rare Earths: Their Occurrence, Chemistry, and Technology - Stanley Isaac Levy - Страница 57

Approximately E₂O₃, (Cb,Ta)₂O₅, with U, Fe, Ca. Cer = 0·5-13·9; Yttr = 27·9-47·1; ThO₂ + ZrO₂ = 0-7%. [Berzelius found Cer = 36·3; Yttr = 0% in one specimen.]

Tetragonal, polar.

G = 5·84-4·3 when largely hydrated. H = 5·6. Brown to black.

Norway; Australia; Texas, etc.