pyrochlore

[ pahy-ruh-klawr, -klohr ]
/ ˈpaɪ rəˌklɔr, -ˌkloʊr /

noun

a mineral, chiefly composed of niobates of the cerium metals, occurring in syenites in the form of brown crystals.

Origin of pyrochlore

From the German word Pyrochlor, dating back to 1820–30. See pyro-, chlor-1