[whswhs]

Hmmm. I think your basic power is Control Nonliving Matter, which is broader than any of the Common categories; I would give it a base of 30 points. But you might also look at Create (Transmutation Only) with at least a Large category. This would give you a very flexible power. Take a look at the special effects it permits, and if there's any effect they don't provide, but that you want the character to have, ask about that.