Mineral profile Niobium-Tantalum - British Geological Survey
Niobium–tantalum 2 Figure 2 Pyrochlore. Source: Rob Lavinsky (iRocks.com)2. Other, less common oxides of niobium and tantalum include tapiolite, ixiolite, and minerals of the perovskite group. Niobium and tantalum also substitute for major ions in some common oxide groups such as cassiterite, rutile, and ilmenite.