METAL: 18k Gold. MEASUREMENTS: Necklace is 17 1/2" long, clasp is 11.5mm in diameter. GEMSTONES; Carved aquamarine beads - 5.7mm to 10.7mm. MARKED: N1124, 750, 18k, Buccellati on clasp. WEIGHT: 30.8 grams.Gemstones have not been graded for color and clarity ,and tested for clarity and color enhancement, unless stated otherwise.