Niobium was first found in 1801 by the English chemist Charles Hatchett, in a mineral sample sent from Connecticut; he called it columbium, after Columbia, a poetic name for America. Because it so resembled tantalum and the two were repeatedly confused, the German chemist Heinrich Rose renamed it in 1844 as niobium. It is a soft, grey, ductile metal important in superalloys and, above all, in superconducting magnets. Niobium is added to steel to make strong, light alloys for pipelines and vehicles, and its compounds with tin and titanium turn superconducting when chilled, making the metal indispensable to the powerful magnets of MRI scanners and particle accelerators.
Niobium, like titanium, can be anodised to grow a thin, transparent oxide layer whose thickness determines which wavelengths of light interfere and reflect, producing a full spectrum of colours on the metal's surface without any dye or pigment; the effect, combined with niobium's hypoallergenic resistance to skin reactions, has made it a popular material for body jewellery and wedding rings. Niobium-titanium alloy wire remains the standard superconducting material for the powerful magnets of the Large Hadron Collider and the great majority of the world's MRI scanners, chosen for a practical balance of superconducting performance, cost and mechanical workability that purer or more exotic superconductors have yet to beat.