The diamond girdle is an often-overlooked part of a diamond, but it plays an important role in the diamond's overall appearance and durability. The girdle is the outer edge of the diamond that separates the crown and pavilion. When selecting a diamond, it's important to consider the girdle's thickness and finish, as this can impact the diamond's durability and reflectivity. Choose a diamond with a quality girdle for a stunning and long-lasting piece of jewelry.