Green Turtle Necklace in Sterling Silver with Vitreous Enamel (hard fired glass which is painstakingly applied by hand to sterling silver). Adjustable 18 inch chain included.Rhodium Plated for easy care. Fired Enamel is created when liquid glass is fused to metal at temperatures of up to 1500 F. Our enamel colors come from blends of rare metals like gold, cobalt and manganese, with each color requiring a different firing temperature. Designs with several colors require multiple firings to create lustrous color that never fades.