Molybdenum n. (Chem.) A rare element of the chromium group, occurring in nature in the minerals molybdenite and wulfenite, and when reduced obtained as a hard, silver-white, difficulty fusible metal. Symbol Mo. Atomic number 42. Atomic weight 95.94.
... hack saw that will eat through molybdenum steel like so much cheese, and it just wore its teeth off. I tried some of those diamond rotary saws you have, attached to an electric motor, and it wore out the diamonds. That got my goat, so I tried using a little force. I put it in the tension testing ... — The Black Star Passes • John W Campbell