dufrenite

from The Collaborative International Dictionary of English v.0.48

Dufrenite \Du*fren"ite\, n. [From ??ierre Armand Dufr['e]noy, a
   French geologist.] (Min.)
   A mineral of a blackish green color, commonly massive or in
   nodules. It is a hydrous phosphate of iron.
   [1913 Webster]