( n. )
A brownish black mineral with a metallic luster, found in Norway. It contains niobium, titanium, yttrium, and uranium, with some other metals.
( n. )
A brownish black mineral with a metallic luster, found in Norway. It contains niobium, titanium, yttrium, and uranium, with some other metals.
Webster's Revised Unabridged English Dictionary. Пересмотренный полный словарь английского языка Webster. 2012