Green Tourmaline & Diamond Ring. This spectacular ladies vintage-style ring is made in 18Kt white gold. The center stone is a Brazilian cushion cut, dark green tourmaline that weighs 3.58 carats, a pure green color, VS clarity, EX cut (very brilliant). It is further accented by straight baguette cut diamonds totaling 0.19 carat, and round full cut diamonds totaling 0.56 carat, G color grade, VS2 clarity grade, VG cut grade. The ring weighs 11.5 grams.