COLUMBITE

kəˈləmˌbīt noun

( -s )

Etymology: New Latin columb ium + English -ite

: a black mineral that is essentially an iron columbate (Fe,Mn)(Cb,Ta) 2 O 6 grading into tantalite and having a bright submetallic luster (hardness 6, specific gravity 5.4-6.5)