Bon Chef 5017BLK Aluminum Oyster/Clam Plate, 10-1/2" Diameter, Black (Pack of 3) Plate, Clam/Oyster Sandstone retains cold better than china or melamine Safe temperatures -20 degree F to a maximum temp of 185 degree F Bon Chef Sandstone is our pewter glo inserts coated with a china like glaze to make it look like china Do not use iodine-based sanitizers - may cause staining