april is the month of rebirth and renewal, and what better way to mark a new beginning than with a birthstone charm? our serendipity april birthstone charm marks moments big and small: diamonds are said to symbolize purity, strength, and eternal love. add it to your favorite necklaces and bracelets to celebrate the beauty of life. this charm fits over most necklaces and the internal diameter is approximately 2.8 x 2.2 mm.