Molybdenite

from WordNet (r) 3.0 (2006)

molybdenite
    n 1: a mineral resembling graphite that is valued as the chief
         source of molybdenum and its compounds

from The Collaborative International Dictionary of English v.0.48

Molybdenite \Mo*lyb"de*nite\, n. [Cf. F. molybd['e]nite. See
   {Molybdena}.] (Min.)
   A mineral occurring in soft, lead-gray, foliated masses or
   scales, resembling graphite; sulphide of molybdenum.
   [1913 Webster]