Rifts of the Taies
The Air Stone resembles a small, clear, cloudy white stone.
This stone is one of several different elemental stones (Air, Fire, Water, Earth, etc) which allows the user to replenish one used spell slot. Each spell level of a replaced spell will permanently use up one charge (a 1st level spell uses 1 charge, a 3rd level spell uses 3 charges, etc.). Comes with 100 charges. After the charges are used, the stone becomes just a normal, non-magical stone.