Stone: Natural Amethyst Quartz
Frame Material: 18K Gold Plated Over Solid Genuine .925 Sterling Silver.
Shape: Faceted coin both sides
Measurement: 20mm with both rings, stone size is 12mm
Weight: 1.4 grams per piece.
These stones are known as hydrothermal quartz, which contains the same physical, chemical and optical properties of a natural stone. For further information and details regarding this process, see the Beadunion Blog: http://www.beadunion.com/bezel-gemstone-information