Diameter: Approximately 7.5mm Circumference: Approximately 17cm (Please allow for some margin of error) As this is a natural product, there may be some scratches, dents, cracks, and inclusions. Please understand this before purchasing. Due to online sales, the color of the product may differ slightly from the photos. We try to upload photos that are as close to the actual color as possible. Also, the photos are taken to appear larger, so the actual product may be smaller than you imagine.