Isomeric with [Johnstrupite] (q.v.).
G = 2·93-3·03. H = 4. Reddish brown; translucent.
Langesund Fiord, Norway.
Muromontite.
A variety of [Allanite] (q.v.), rich in yttria earths and Be, but poor in Al and ceria earths. Cer = 9·1; Yttr = 37·1%.
See [Allanite].
G = 4·263. H = 7. Black to greenish black.
Mauersberg, Erzgebirge, Saxony.
Naegite.
A silicate of Zr, ZrSiO₄, with E, Th, U, Cb, etc. ZrO₂ = 55·2; Yttr = 9·12; ThO₂ = 5·01%.