uter diameter: 150mm (6 inch) Aperture: 12.7mm Thickness: 1.0 mm Material: cooper Quantity: 1 pc The purple copper polishing disc is suitable for polishing various gemstones, including diamonds, sapphires, rubies, emeralds, and more. It enhances the luster and surface details of gemstones. It is also effective in polishing materials like pearls, removing fine scratches and restoring their shine. Whether it's for repairing gemstones or enhancing their appearance, the purple copper polishing disc is an ideal choice.