Peridot Birthstone Emerald Cut Diamond Ring 10K Yellow Gold10k yellow gold diamond and emerald cut peridot birthstone ring. The perfect August birthstone ring or mothers ring, this 10 karat yellow gold band has emerald cut peridot and diamonds alternating half way around the ring. All birthstone rings and mother's rings are available in all birthstones, although the April (diamond) version may cost more. Looks great worn alone, or as a stackable ring. Finger Size 9