The Collaborative International Dictionary of English v.0.48:

Mineralize \Min"er*al*ize\, v. t. [imp. & p. p. Mineralized;
   p. pr. & vb. n. Mineralizing.] [Cf. F. min['e]raliser.]
   [1913 Webster]
   1. To transform into a mineral.
      [1913 Webster]

            In these caverns the bones are not mineralized.
                                                  --Buckland.
      [1913 Webster]

   2. To impregnate with a mineral; as, mineralized water.
      [1913 Webster]

   3. To charge or impregnate with ore.
      [Webster 1913 Suppl.]

The Collaborative International Dictionary of English v.0.48:

Mineralize \Min"er*al*ize\, v. i.
   To go on an excursion for observing and collecting minerals;
   to mineralogize.
   [1913 Webster]

WordNet (r) 3.0 (2006):

mineralize
    v 1: convert into a mineral substance
    2: transform (a metal) into an ore