author(s) : Broegger
date of publication : 1897
source : Vidensk.Selskr.Oslo, Mat.-Nat.Kl.(7) p.3
formula : (Fe,Mn)(Nb,Ta)2 O6
comments about the origin : etiquette Univ.Min.Geol.Mus.(Oslo) ech.1974
This type specimen, kept in the Museum of Ecole des mines de Paris, has been indexed by Dr Guillemin.
(C) BRGM, ENSMP