COLUMBITE (Iron Manganese Magnesium Niobium Tantalum Oxide)
Chemical Formula: (Fe, Mn, Mg) (Nb, Ta) 2 O 6, Iron Manganese Magnesium Niobium Tantalum Oxide. Uses: An ore of niobium and tantalum and as mineral specimens. Columbite is the most widespread niobium mineral and makes for an important ore of the industrially useful metal. Niobium, Nb, is used in alloys for improved strength.
