If you are planning to buy an antique ruby diamond ring, the following are some great designs you can choose.     Edwardian Design with Cushion Cut Ruby This style features a cushion cut ruby as the centerpiece with a single halo setting surrounding it. The band has round brilliant diamond accents and milgrain details on it. Art Deco Design with Oval Ruby In this style, a vivid oval cut ruby is the centerpiece surrounded by a double halo of round brilliant diamonds. The band is plain and made of platinum.     Retro Design with Round Ruby The Retro Era design features a bezel set round ruby stone as the centerpiece and the band style is a split-shank band made of white gold. Victorian Style with Cushion Cut Ruby In this antique style of ruby engagement rings with diamonds, the centerpiece is a cushion cut ruby with a floral halo of diamond accents set on a yellow gold band.   Edwardian Design with Radiant Cut Ruby This Edwardian style ring features a glittering radiant shaped ruby center stone surrounded by a halo of diamond accents in a platinum band.