Cobalt

Cobalt is chemical element with the symbol Co and atomic number 27. Cobalt is a ferromagnetic metal. It is a naturally-occurring element, and is commonly found in a number of ores. Cobalt is used in numerous alloys, and some cobalt-based materials are also used in weapons.

The antimatter relays of an NX class starship are lined with a platinum-cobalt alloy. (ENT: "The Xindi")

In 2154, the Enterprise (NX-01) carried 18 kilos of tritanium-cobalt, of which nine were used to bribe guards in releasing slaves on the Verex III Orion processing station. (ENT: "Borderland")

The Lysian Central Command space station was armed with 39 cobalt-fusion warheads. (TNG: "Conundrum") Other military uses of cobalt include cobalt-thorium devices, cobalt bombs and the nerve agent cobalt diselenide. (DS9: "The Maquis, Part I", "For the Uniform"; TOS: "Obsession")

The body of the Soong-type android Data included 11.8 kilograms of molybdenum-cobalt alloys. (TNG: "The Most Toys")

According to the Star Trek: The Next Generation Interactive Technical Manual, written by Michael Okuda and Rick Sternbach, a metallic alloy of tungsten-cobalt-magnesium was used to form the structural core of a warp coil. It provided the rigidity and high heat tolerance required due to the prolonged exposure to warp plasma.