Heart Of The Metal

Transmutation [earth]
Level: Artificer * 3, Magus * 3, Sorcerer */Wizard * 3, Warlock * 3
Components: V, S, M (a chunk of adamantine worth 100 gp, or a chunk of cold iron or silver worth 20 gp)
Casting Time: 1 Standard Action
Range: close (25 ft. + 5 ft./2 levels)
Target: one weapon per level
Duration: 1 minute/level (see text)
Saving Throw: None
Spell Resistance: no
  You lend the nature of Adamantine, Cold Iron, or silver to the targeted weapons, depending on which component you used, with the following effects. Adamantine: The weapons overcome DR/Adamantine and ignore Hardness of less than 20. Cold Iron: The weapons overcome DR/Cold Iron. Silver: The weapons overcome DR/silver. No other advantages or disadvantages of these metal types apply. For example, a weapon given the nature of Adamantine is not automatically masterwork. This spell can affect nonmetal weapons. If you grant the target weapons the property of Cold Iron, the spell lasts half as long as normal.