Retro Two Stone Old European Old Mine Cut Diamond Ring.  This delightful Retro engagement ring features a .80 carat Old European cut and a .89 carat Old Mine cut diamond set uniquely in 14 karat white and yellow gold. The stones are set with fishtail prongs in white gold with a lovely bypass design and actually share one of the prongs, which brings some uniformity. This would make a wonderful ring for someone who loves vintage and is looking for something stylish and asymmetrical.