noun
columbite
A mineral, (Fe,Mn)Nb₂O₆, used as an ore of niobium. Technical term in mineralogy.
コルンブ石はニオブの重要な鉱石鉱物である。
Columbite is an important ore mineral of niobium.
From English 'columbite', named after the element columbium (an old name for niobium).