Moon Phase Ring Waterproof Details: • MATERIAL: PVD, 18K gold plated over stainless steel, or stainless steel • Size: Cuff Ring US 6.5 What is PVD Jewelry? Physical Vapor Deposition, is a process used to coat jewelry with a thin layer of metal. PVD have several environmental benefits compared to traditional gold plating, vermeil, and other metal finishes.