Crystal Magic Weapon

You touch a non-magical weapon OR a weapon that is magical only in the sense that is a +1, +2, or +3 weapon. The weapon gains a blue aura, and small pale crystals adorn the weapon. If the weapon deals any additional damage besides the bonus of having a plus, then this spell will not work. Until the spell ends, that weapon has a +4 bonus to the attack and damage rolls. If the weapon is a +1, etc., then the bonus stacks. In addition, the weapon also deals an additional 1d6 force damage.

If the spell is cast at 9th level, then the bonus is a +5.