TantaliteFe

Tantalite-(Fe), commonly referred to as ferrotantalite, is the iron-rich member of the tantalite-columbite solid-solution series. It is a mineral in the oxide family and is defined by the dominance of iron at the M-site with niobium and tantalum comprising the Nb/Ta framework. The name tantalite-(Fe) is the IMA-recognized designation for this endmember, while ferrotantalite is a traditional name still encountered in ore geology.

Composition and structure: Tantalite-(Fe) forms a continuous solid solution with tantalite-(Mn) and columbite, with the general formula (Fe,Mn)Nb2O6 and occasional Ta substituting for Nb. In tantalite-(Fe) iron is the principal cation on the M-site, and manganese can be present as a subordinate substituent. The relationship among Fe, Mn, Nb, and Ta gives rise to a range of compositions within the same mineral group.

Occurrence and geology: Tantalite minerals occur in oxidized segments of granitic pegmatites and hydrothermal veins, as well as in certain pegmatite-rich ore deposits. They are widely reported in Africa (notably the Congo region), as well as in Australia, South America, and other mining areas. In samples, tantalite-(Fe) often coexists with other niobium-tantalum minerals such as cassiterite, spodumene, and various oxides.

Economic significance: Tantalite is the principal ore mineral for tantalum, a metal essential in electronic capacitors, specialty alloys, and other high-tech applications. The iron-rich endmember tantalite-(Fe) can influence ore processing and the distribution of elements in concentrates, which has implications for mining and compliance with trade and sourcing standards.

See also: ferrotantalite; tantalite-(Mn); tantalum; columbite-tantalite series.