Solid Sterling Silver Rhodium Plated 10mm Black Simulated Onyx Pendant Necklace, 16" 18" 20" 24" Unsure what length chain to buy? 18 inches is the standard length and will look great on most people To purchase the pendant by itself (without a chain), choose the "0.0 inches" length This pendant necklace is made of solid rhodium plated sterling silver and fine quality simulated onyx The diameter of the pendant is 10mm (0.39 in), the chain is 0.8mm thick and either 16, 18, 20, or 24 inches long Made in-house at Beauniq Fine Jewelry in NYC