Gothic Black Onyx and Sterling Silver Poison Box Locket Ring(Sizes 5,6,7,8,9,10) Genuine Black Onyx Stone Inlay (Dyed) Small Hidden Secret Compartment (about 1/4" x 3/8") Weight is Approx. 4.5 - 4.7 Grams About 3/8" (10mm) Across on Top Marked 925 for Sterling Silver