1) Iron mineral 2) Oxide mineral
Found on
https://www.crosswordclues.com/clue/tapiolite
Tapiolite [(Fe, Mn)(Nb, Ta)2O6] is a black mineral series that is an ore of niobium and tantalum. The tapiolite group includes tapiolite-(Fe) or ferrotapiolite and tapiolite-(Mn) or manganotapiolite. Tapiolite-(Fe) is by far the more common of the two. The minerals have a submetallic luster and a high specific gravity with tapiolite-Fe having a hi...
Found on
http://en.wikipedia.org/wiki/Tapiolite
No exact match found.
