skutterudite

from The Century Dictionary.

• noun An arsenide of cobalt found in tin-white to lead-gray isometric crystals, also massive with granular structure, at Skutterud in Norway. Also called by the Germans tesseralkies.

from the GNU version of the Collaborative International Dictionary of English.

• noun (Min.) A mineral of a bright metallic luster and tin-white to pale lead-gray color. It consists of arsenic and cobalt.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun mineralogy A class of mixed cobalt and nickel arsenide and sulfide minerals