Touch of Decay

You cause one of your hands to glow with a reddish brown glow, and any non living objects that you touch begin to decompose, corrode, and crumble. 

As an attack action you can touch a non living object that you can reach and deal 1d8 Necrotic damage to it. If the object is being worn or carried you must make a successful touch attack against the creature that is wearing or holding the item, dealing the damage on a successful hit. If the object is a weapon, rather than taking 1d8 damage it instead gains a cumulative -1 penalty to its damage bonus. If the object is a suit of armor or a shield, it instead takes a cumulative -1 penalty to its Armor Class or Armor Class bonus. Weapons that are reduced to a total damage bonus of -5 are destroyed. Armor that no longer provides protection (Armor Class 10), and shields that do not provide any bonus to Armor Class are destroyed

Magic items and enchanted objects (not weapons or armor) have Resistance to this damage. If a magic item, weapon, suit of armor, or shield is destroyed its enchantment is lost. This spell cannot deal damage to living creatures, however constructs are not immune.

At Higher Levels: when cast using a spell slot of 3rd level or higher the damage caused is increased by 1d8 or an additional -1 for each additional level.