september is the month of balance and harmony, and what better way to recentre and ground yourself than with a birthstone charm? our serendipity september birthstone charm restores balance and harmony with sapphire. sapphire is said to promote wisdom, truth, and balance. add it to your favorite necklaces and bracelets to find equilibrium with the harmony of life. this charm fits over most necklaces and the internal diameter is approximately 2.8 x 2.2 mm.