Necklace (a7)-Type: Necklace Stone: Yellow Opal Gemstone Stone Detail: Natural Quantity: 1Strand Material: Silver Plated Over Copper Clasp Weight: 96.39 gram. Length: 18 1/2" Stone Size: 1x6x5mm-5x10x5mm Hardness: 5.5 Conversion: 1mm=0.039 inch,1 inch=25.41mm