Melior Metallum is a mod that aims to add many new metals, each with certain unique properties.
Vanadium: A metal with camoflauge properties. If you are wearing the full set of armor, it will turn you invisible. The ore spawns below y-level 24, somewhat more common than diamond, in veins of up to 10. If you make tools from it, they will deal as much damage as diamond, be as fast as gold, and have 500 uses.