30 Carat Ruby & Diamond 18k Yellow Gold Ring. The diamond and rubies are good quality. The diamonds are SI1 clarity G color stones and together have a weight of. 15 carats and has a beautiful light red/pinkish color. The ring is in good condition.It has some light surface wear but no major flaws. It is a size 7.5 and weighs 4.9 grams. The top of the ring is 4.5mm wide. The item "Vintage 18k Yellow Gold. 30ct Red Ruby & Diamond Ring Mens Unisex Size 7.5" is in sale since Thursday, August 9, 2018. This item is in the category "Jewelry & Watches\Fine Jewelry\Fine Rings\Gemstone". The seller is "garcoininc" and is located in Garwood, New Jersey. This item can be shipped to United States.