American, mid - late 20th century. Three rings to include: stamped 18K ring with center oval cabochon opal, accented with four small round rubies (possibly synthetic), small gold heart on each shoulder, Sz 6.5; stamped 10k gold ring with three oval opals across the center, mounting with open work and beading, Sz 8; Together with unmarked gold ring (x-ray tested 14K) with cluster of five round cabochon opals and four seed pears, Sz 7. Total weight 8gr.