Pyrochlore \Pyr"o*chlore\, n. [Pyro- + Gr. ? pale green.] (Min.)
A niobate of calcium, cerium, and other bases, occurring
usually in octahedrons of a yellowish or brownish color and
resinous luster; -- so called from its becoming grass-green
on being subjected to heat under the blowpipe.
[1913 Webster]