|
| |
- An orthorhombic mineral, (U,Fe,Y,Ca)(Nb,Ta)4 (?) ; opaque black; at
Ishikawa, Iwaki Province, Japan.
Source:
Dictionary of Mining, Mineral, and Related Terms
- (U, Fe, X) (Nb, Ta)O4
X = rare earths.
U = 19.3 percent.
Color: Black. Rare, from granite pegmatites.
Source: Frondel, Judith Weiss and Michael Fleischer. 1955. Glossary of
Uranium- and Thorium-Bearing Minerals, Third Edition. Washington DC: United
States Government Printing Office
| |
|
