Minor Alchemy

Starting at 2nd level when you select this school, you can temporarily alter the physical properties of one nonmagical object, changing it from one substance into another. You perform a special alchemical procedure on one object composed entirely of wood, stone (but not a gemstone), iron, copper, or silver, transforming it into a different one of those materials. For each 10 minutes you spend performing the procedure, you can transform up to 1 cubic foot of material. After 1 hour, or until you lose your Concentration (as if you were Concentrating on a spell), the material reverts to its original substance.