- An isometric mineral, (Ca,Na,U)2 (Ti,Nb,Ta)2 O6 (OH);
pyrochlore group; forms a series with pyrochlore; name assigned to
members of the series having uranium greater than 15%; radioactive; in
granitic pegmatites. CF: uranpyrochlore
Dictionary of Mining, Mineral, and Related Terms
- (U, Ca)(Nb, Ta, Ti)3O9�nH2O
Composition uncertain; name includes several supposedly independent species
that have been united on basis of X-ray and crystallochemical study.
U = 13.7 to 24.5 percent, Th = 1.0 to 1.1 percent.
Color: Yellow, brown, black. From granite pegmatites.
Synonyms and varieties: blomstrandite (synonym, U = 16.3 percent), mendeleyevite (titanian
betafite, U = 13.7 percent), and samiresite (has been considered a plumbian variety,
U = 18.7 percent).
Source: Frondel, Judith Weiss and Michael Fleischer. 1955. Glossary of
Uranium- and Thorium-Bearing Minerals, Third Edition. Washington DC: United
States Government Printing Office