Niobium

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.

Rose's choice of name was a deliberate piece of mythological wit. Niobium is found together with, and is chemically almost inseparable from, the element tantalum, which had itself been named after Tantalus, the Greek king punished in the underworld. In the myth, Niobe was the daughter of Tantalus, a queen whose boastful pride cost her all her children and who was turned to weeping stone. By naming the sister element after Tantalus's daughter, Rose fixed their close kinship in the language of myth.

The old American name columbium lingered in the United States for over a century, and only in 1949 did niobium become the international standard, though columbium is still occasionally heard in metallurgy. The myth itself is one of Greek tragedy's starkest: Niobe, queen of Thebes, boasted that her fourteen children made her superior to the goddess Leto, who had only two, Apollo and Artemis; the offended twins slew all of Niobe's children before her eyes, and Niobe wept until the gods turned her to stone on Mount Sipylus in Anatolia, where a weathered rock formation is still shown to visitors as her petrified, eternally weeping form. Niobium and tantalum, sharing both a myth and a mineral, are the periodic table's clearest father and daughter pairing drawn from a single family story, a small piece of narrative continuity in a table otherwise built from scattered, unrelated names.