Rings › Style #659 Image 1 of 1 Style #659 $0.00 18k gold ring with 9x7.5mm rectangular center stone and six 2.1mm round Diamonds. Shown in Bi-Color Tourmaline. Add To Cart Added! 18k gold ring with 9x7.5mm rectangular center stone and six 2.1mm round Diamonds. Shown in Bi-Color Tourmaline.