niobium

noun

Etymology: From Niobe + -ium, because of the element's affinity with tantalum, named after Niobe's father Tantalus.

1. A chemical element (symbol Nb) with an atomic number of 41: a light grey, crystalline, ductile transition metal used in superconducting materials.

   “One should use hypoallergenic jewelry made of surgical grade stainless steel, titanium, 14- or 18-karat gold, or niobium, especially for initial piercings.”

2. A single atom of this element.