Читать книгу The Rare Earths: Their Occurrence, Chemistry, and Technology - Stanley Isaac Levy - Страница 126

A silicate of E, Fe, Na, Th, Mn, Al, Ti, H₂O, etc.; near Melanocerite. Cer = 14·4-32·5; Yttr = 0-15·9; ThO₂ = 2·1-7·1%.

Rhombohedral.

G = 3·38. H = 4. Brown; faces dull.

Kangerdluarsuk, Greenland.