Columbite-Tantalite (Coltan)
Image: <bdi><a href="https://www.wikidata.org/wiki/Q56247090" class="extiw" title="d:Q56247090"><span title="mineral collector and dealer">Robert M. Lavinsky</span></a></bdi> (CC BY-SA 3.0)
Mineral NameColumbite-Tantalite (Coltan)
Chemical Formula(Fe,Mn)(Nb,Ta)2O6
Mohs Hardness6
Crystal Systemorthorhombic
Streak Colordark red to black
Cleavagepoor on {010}
Fractureuneven
Specific Gravity6.5
Colorsblack, brownish-black, yellowish-brown
Transparencyopaque
Type LocalityDemocratic Republic of Congo
Mineral GroupOxides
Useselectronics, high-temperature alloys, superalloys
Associated Mineralsquartz, feldspar, cassiterite, wolframite
Rarityuncommon
Description
A dark, elongated, prismatic crystal with prominent vertical striations, exhibiting a submetallic luster and some yellowish-brown surface alteration.
Geological Context
This mineral series is primarily found in granitic pegmatites and alluvial placer deposits, serving as a key source of tantalum and niobium.
