The Philippa is a stud earring with round shaped cubic zirconia stones.
Base Metal: 925 Sterling Silver
Plating: 18K Yellow Gold or Rhodium
Stone: Clear Cubic Zirconia
Details: 2.5mm .05 and 3.8mm .20 carats. Push back 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.