Crossword clues for the word: NIOBIUM The word NIOBIUM has appeared as an answer to at least 9 crossword clues on different crossword puzzles. Crossword clues for NIOBIUM Showing 1 to 9 of 9 results Clue(s) Ductile white metallic element; symbol Nb Element #41 Element in stainless steel Element named for a mythical Greek weeper Element named for a mythical queen Element used in alloy steels Its principal ore is columbite Metallic element Steel-gray Element