18K Yellow Gold Scalloped Cathedral Halo Diamond Engagement Ring. This engagement ring features a cathedral style band with stunning scalloped common prong settings that contour the round brilliant diamonds. The center stone is surrounded by a halo and held by four prongs with ball tips. Number of diamonds and total carat weight listed on the product information is based on a 1 ct. center stone. Please note that the number of diamonds and total carat weight may vary according to the size and shape of the center stone.