The Silver Acorn is the Starwives' badge of office, worn around their necks. In legend, the silver acorn was found hanging from a branch of an oak tree by the first squirrel to awaken in the deeps of time. Before the Starglass was destroyed, young squirrel maidens wishing to become the Handmaiden of Orion needed to join the acorn with it and allow the magical powers to channel through them. Then they would truly be the Starwife.
In The Oaken Throne, a penegrine falcon taking the silver acorn to safety was killed by bats, and so the squirrelmaiden Ysabelle caught the pendant as it fell from the sky. This begins her journey to become the Starwife.