columbite /kəˈlʌmbaɪt/

• 1. 

  N a black mineral consisting of a niobium oxide of iron and manganese in orthorhombic crystalline form: occurs in coarse granite, often with tantalite, and is an ore of niobium. Formula: (Fe, Mn)(Nb)2O6 钶铁矿 (Also called niobite)