Plain Round Black Agate (Onyx) Modern Silver Ring Plain Round Black Agate (Onyx) Modern Silver Ring made by 925 sterling silver. On ring settled round black agate (onyx) stone settled. Rhodium plated shine and plain body. Suitable for daily use and pinky fingers. Back side is open to allow stone touches your skin. Total weight of ring is about 7 gr. (depends your ring size.) Designed and made in Turkey by Boutique Ottoman Jewelers.