Beautifully carved Shell Cameo Gold Filed Brooch Diamond (500pcs)?. Circa 1920

Beautifully carved Carnelian shell cameo brooch. Brooch measures approximately 44mm. x 36mm. & weight 7.06 gram. Previous owner told me that diamond is 500pcs but I’m not specialist in that. Few almost unnoticeable stress lines - except this pease in good condition. May be need some cleaning on the back. Bezel marked 1/20 10K. Circa 1920. Very Nice for Collection - Beautiful Present