A cromium- and magnesium-rich variety of ilmenite, containing up to 8.6% Cr2O3 and up to 17.0% MgO. Ferrian Ilmenite containing up to 33% Fe2O3 in solid-solution in the rhombohedral series Fe2O3-FeTiO3. Guadarramite A supposed radioactive variety of ilmenite : Hystatite A ferrian variety of ilmenite. On material from Arendal. …