Crystalsmith

You have mastered the necessary skills to infuse weapons with powers, gaining the following benefits:

• As part of a short rest, You can touch a nonmagical weapon and expend 50gp worth of precious gems. That weapon becomes a magic weapon infused with crystals of power.
• According to which gems you used, you can choose to change the damage type of the weapon according the following table:  

                 Gem Type                 Damage Type
                     Ruby              -                 Fire
                     Jade              -                 Acid
                Lapis Lazuli       -                Cold
               Moonstone         -              Psychic