Читать книгу The Rare Earths: Their Occurrence, Chemistry, and Technology - Stanley Isaac Levy - Страница 35

Complex fluosilicate of E, with Ta, Th, Ca; also CO₂, P₂O₅, B, Al, Fe, Mn, U, Mg, Na, aq., etc. Approaching Melanocerite, (q.v.), but richer in Th. Very complex. Cer = 41·8; Yttr = 2·2; ThO₂ = 13·6; ZrO₂ = 0·5%.

Rhombohedral, but isotropic; apparently a pseudomorph after Melanocerite (q.v.)

G = 4·295. H = 5-6. Nut brown; translucent. Faces very brilliant, but striated. Lustre vitreous to resinous.

Various rocks and shoals round Arö Island, Langesund Fiord, Norway.