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Columbite-(Mn)

Year of discovery: 1892 (World), 1960 (Japan)

Locality list: 2 localities of columbite-(Mn)

• MnNb₂O₆
• (Mn,Fe²⁺)(Nb,Ta)₂O₆
• [Mn²⁺][(NbO₃)₂]^2-

• Class: Columbite series - Tantalite group
• Class: Niobate
• Soluble in: HCl (Decompose)

• Mn => Fe: Columbite-(Fe) (Series)
• Mn => Mg: Columbite-(Mg)

• NbO₃ => TaO₃: Tantalite-(Mn), Tapiolite-(Mn)

• Color: Black
• Streak: Dark brown
• Luster: Sub-Metallic
• Diaphaneity: Opaque

• Habit: Long tabular

• Cleavage: Distinct on {010} (1 plane), Indistinct on {100} (1 plane)
• Hardness: 6
• Density: 5.3

• System: Orthorhombic
• Group: mmm, Pcan
• Lattice: a=5.8, b=14.4, c=5.1

Etymology: Columbia, synonym of USA

Synonym: Manganocolumbite