Noranium was an element used to create alloys.

Noranium vaporized at 2,314 °C, and noranium carbide at a slightly higher temperature. When heated, it released a vapor which forms clouds of smoke. Burning noranium could be extinguished with sand. A Starfleet type-2 phaser at setting 7 could heat noranium to the vapor point.

Noranium alloys had a very low scrap value, but were still collected by the Gatherers. (TNG: "The Vengeance Factor")