Ooooh... pick me, I actually learned this recently. A...

Ooooh... pick me, I actually learned this recently. A 'pyrochlore structue' descibes a certain type of mineral structure at the atomic level, probably after natures pyrochlore mineral structure, but nothing to with Nb specifcially. Many different compounds exhibit or are made that exhibit the 'pyrochlore structure', inclusing Nb2O5 apparently. Serioulsy, google it.

Back to the same issue though, Nb2O5 is the oxide molecule of pure Niobium. The mineral pyrochlore is a Na, Ca, OH/F, Oxide not Nb2O5. Pyrochlore the mineral found at Luni is inert for all intents and purposes.. that path is a dead end

Good try though, cheers