Look at the beautiful! Rough side with a twist band on both sides of the stone. *All natural semi-precious Blue Apatite gemstone. *Measurement for Center Stone is Approximate between 10-15mm (will range) *Sterling Silver/.925 Silver This picture is an representation of the type and quality of the gemstone you will be receiving. As you know, there are slight variations due to the natural character of this product. -All information about the metaphysical properties of crystals is for reference only. It is a combination of research on how gemstones have been used by different cultures today & throughout history. We do not recommend using crystals as a substitute for conventional medical advice.