.16 Diamond Turtle Stacking Ring in 18k White Gold. 16 Diamond Turtle Stacking Ring in 18k White Gold. This fashionable stacking ring features . 16 carats of sparkling diamonds finished in polished 18 karat white gold. Seven (7) . 0228 carat diamonds are set at the head of the ring. The mounting detail of the ring is shaped like a turtle, with the diamonds set in surface prongs on the shell of the body. Finished on a thin, 18k white gold band, this stylish stacking ring would make a one of a kind