展开The Enamel used on these pieces is a type of allochromatic glass that consists usually of quartz sand, iron oxide, potassium oxide (potash) and borax (flux). These components form;a transparent and colorless fondant after firing at temperatures between 700 and 900 degrees Celsius. Their plethora of colors are established by addition of different metal oxides and/or chlorides. After thoroughly crushing and washing these materials a hydrated mass is formed (a fondant) which is then applied on a suitable, and completely clean metal. 18ct gold with brillaint cut diamonds. The ring measures 15mm wide by 18mm long.; US Size 6.