925 Silver ring, gold-plated (3 to 5 microns) and Amethyst (1cm). For any Pre-order, you can choose the semi-precious stone, the desired sizes and the plating. For a rose gold or black rhodium plating, please contact us. Normally the rates are the same as for gold plating. If you would like a fine stone other than those offered to you, thank you in advance for contacting us in order to provide you with prices. “Nombre d'Or” collection Important note: Colored chalcedony (aqua, ocean blue, etc.) returns to its initial color (milky white) over time. To best preserve the color, avoid exposing them to the sun.