Arrhenite, Chalcolamprite, Endeiolite and Wöhlerite, are complex tantalo-columbates containing silica.
Hainite contains both silicon and titanium.
Dysanalyte is a titano-columbate believed by Hauser[76] to be merely an impure form of perovskite (see [p. 14]).
[76] Vide Zeitsch. anorg. Chem. 1908, 60, 237.
Ilmenorutile and Strüverite are closely allied minerals believed by Prior[77] and Schaller[78] to be isomorphous mixtures of rutile with Tapiolite or Mossite (ferrous tantalo-columbates).
[77] Min. Mag. 1908, 15, 78.
[78] Abstr. Chem. Soc. 1912, 102, ii. 773.
Pyrochlore is a complex titano-columbate containing elements of the cerium or yttrium groups.
Blomstrandite is an hydrated titano-columbate of rare earth elements, with calcium and uranium; it must not be confused with blomstrandine.