Original Art Deco Cabochon Sapphire Old Mine Cut Diamonds 18K Gold Ring. This is a beautiful original art deco ring set with a natural cabochon sapphire and two old mine cut diamonds. The cabochon sapphire is natural blue gem quality with nice bright blue color and great clarity aproximately 2 carats. The diamonds are .20 carats each I color SI-1 clarity. Ring is in excellent condition, Ring Size 7, Face of the ring measures 14mm by 10mm, Weight 4.5 grams marked 18k.