Vintage Grecian Goddess Intaglio Cameo Necklace

Beautiful! I know this is one of the famous Grecian Goddesses, but I have no idea who she was! No signs of wear on the crystal pendant. The chain passes the magnet test for Sterling, however the clasp does not. The chain is so very delicate, I have yet to run into a chain this delicate & it not being sterling, but, there are no markings, & even though it passes the test, I cannot say. The pendant is two inches long, 1 1/2 wide set in ornate, silver tone bezel.