thorogummite

from The Century Dictionary.

• noun This mineral, like other native compounds of thorium and uranium, has marked radioactive properties.
• noun A mineral occurring in massive forms of a dull yellowish-brown color, and containing silica and the oxids of uranium, thorium, and the metals of the cerium and yttrium groups.

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

• noun mineralogy A tetragonal-ditetragonal dipyramidal mineral containing hydrogen, oxygen, silicon, and thorium.