Base Metal: 925 Sterling Silver
Plating: Yellow Gold
Stone: Synthetic Opal and Clear cubic zirconia.
Details: Outside diameter 1cm. Depth 2mm. Opal size 3.4 mm width, .15 carat. Cubic Zirconia size 1/150. Pushback closure.
Oxidation appears with time as this is just the metal (silver or brass) reacting to the oxygen in the air. Thus, this is considered normal wear and tear and is not a defect.