.925 sterling silver Green Amethyst gemstones = approximately 8.60 ct. tw. The Ring Size Guide(https://s3.amazonaws.com/more-info/guides/ring-size) It is customary to treat most gemstones to achieve enhanced color and durability. Some of these treatments may not be permanent, and may require special care. Please note: In product titles ct. tw. refers to the total carat weight of all diamonds and/or gemstones combined.
