While mining your inventory quickly fills up with stone. When your inventory is completely full everything that you mine with begin to automatically to fall to the ground.
It is easy to miss gems and other nice items if they fall below the dropped stone.
It would be cool if we could get a gem pouch which we could carry with us, either in our inventories or on our belts. The pouch would automatically store mined gems inside of itself.
Only gems would be able to be stored in the pouch