Sterling Silver 12.9-Carat Rainbow Moonstone PendantMaterial: Genuine Sterling Silver (925 silver, 92. 5% silver content) Stone(s): Genuine rainbow moonstone, 12. 9 carats Overall Dimension (including bail): 1. 7 x 0. 9 x 0. 3 inches Inner Bail Diameter: 4 mm Weight: 11. 1 grams Stamp Mark: Starborn, 925 Serial Number: p28828 Moonstone is a variety of orthoclase, a feldspar. It often has a sky blue opalescent sheen, also called schiller or fire, making the stone look as if it is glowing. The sheen is