This necklace is made of solid rhodium plated sterling silver, featuring fine quality simulated opal. Our radiant simulated opal reflects back all the colors of the rainbow, easily convincing others it's the real thing.Necklace comes in 16", 18", 20", 24" lengths or as just a pendant. Pendant measures 25mm (1 in) x 15mm (0.59 in).Choosing Chain LengthUnsure what length chain to buy? 18" is the standard length and will look great on most people. 13" length to 15" length can be worn as a choker on an average size adult. The 16" length will fall just above the collarbone on an average sized adult woman, while the 18" chain will fall just below it. For best results, we do recommend using a tape measure to check neck size before placing your order.About Sterling SilverSterling silver is an alloy of silver. 92.5% of sterling silver is pure silver, and the other 7.5% are other metals (usually copper) that add strength and durability to otherwise soft silverSilver Jewelry CareMost of our jewelry is plated with rhodium to prevent tarnishing and give silver a more expensive, "white gold" look. However, unplated silver will tarnish with time when exposed to air and light. This is natural, and can be easily cleaned with a polishing cloth. Store your sterling silver jewelry in a cool, dry, dark place to avoid faster tarnishing, separately wrapped in a cloth to prevent it from being scratched by other jewelry.