stibiconite

from The Century Dictionary.

• noun A hydrous oxid of antimony, of a pale-yellow color, sometimes massive and compact, and also in powder as an incrustation. Also stiblite.

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

• noun (Min.) A native oxide of antimony occurring in masses of a yellow color.

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

• noun mineralogy An isometric-hexoctahedral mineral containing antimony, hydrogen, and oxygen.