author(s) : Von Knorring and Mrose
date of publication : 1962
source : Progr.Ann.Meeting Geol.Soc.Amer. p.156A
formula : (Bi,Ca)(Ta,Nb)2 O6OH
comments about the origin : Von Knorring 1976
This type specimen, kept in the Museum of Ecole des mines de Paris, has been indexed by Dr Guillemin.
(C) BRGM, ENSMP