Ferrocolumbite
Chemical Formula	Fe2+Nb2O6
Species	Oxides & Hydroxides
Crystal System	Orthorhombic
Mohs Scale	6
Specific Gravity	5.3-7.3
Color	Black, brownish black.
Streak	blackish brown
Luster	sub-metallic
Cleavage	Distinct
Fracture	Sub Conchoidal - Fractures developed in brittle materials characterized by semi-curving surfaces.
Crystal Habit：Massive - Granular - Common texture observed in granite and other igneous rock; Striated - Parallel lines on crystal surface or cleavage face.