Rhombohedral.
G = 4·5-5. H = 5-6. Black; opaque. Slightly magnetic.
Norway; Dauphiné; Bohemia; Cornwall, etc.
Ilmenorutile.
FeO,Nb₂O₅,5TiO₂? TiO₂ = 66-75%.
Tetragonal, very near to [Rutile] (q.v.).
G = 4·3-5·0. H = 6-7. Brown to black; opaque.
Ilmen Mountains, Russia.
Johnstrupite.
Silico-titanate of E, Al, Mg, Ca, Na, etc., with F and aq. Cer = 13·5; Yttr = 1·1; TiO₂ = 7-8; ThO₂ + ZrO₂ = 3·6%.