Pearl of Eldst The Wise
A pearl of pure Arcana.
Once per day on command, a pearl of power enables the possessor to recall any one first level spell that she had prepared and then cast that day. The spell is then prepared again, just as if it had not been cast.
This pearl was created when famed master wizard Eldst the Wise was working on his masterwork spell. He found he could reuse magical energy by capturing it in the pearls as the spell is cast.