Backscattered electron images of columbite-tantalite from the Separation Lake area. (a) Essentially homogeneous ferrocolumbite (at top) with patchy (relatively Nb-rich) ferrocolumbite developed towards the margin of the crystal. Fe-suite Separation Rapids pluton. (b) Homogeneous manganotantalite (bottom left) partially replaced with patchy zoned (mainly) ferrocolumbite (dark regions - top right) and minor microlite (bright regions - top right). Apatite-Li mica-cleavelandite pod in SW subgroup beryl pegmatite. (c) Patchy zoned crystal with variable ferrocolumbite (dark) and manganocolumbite (light) composition - inclusion in Li mica from wall-zone of Mn-suite eastern subgroup petalite pegmatite; Marko's. (d) Large manganotantalite with manganocolumbite (alteration) rim included in microlite. The microlite also contains exsolved blebs of columbite-tantalite (possibly ixiolite), some with a myrmekitic texture. Aplitic unit in Mn-suite eastern subgroup petalite pegmatite; Marko's.

© A.G.Tindle