Читать книгу The Rare Earths: Their Occurrence, Chemistry, and Technology - Stanley Isaac Levy - Страница 59

Basic fluoride of rare earth metals, E₂O₃,4EF₃. Cer = 81·4-82·6; Yttr = 1·1-4·3%.

Massive. Original hexagonal mineral of Berzelius and Haidinger, probably Tysonite (q.v.).

G = 5·7-5·9. H = 4. Reddish yellow; opaque.

Österby, Sweden.