Vintage Round Cabochon cut Amethyst set in 18k Yellow Gold

Vintage 18k yellow gold pendant with a round cabochon cut amethyst stone.  Chain is sold separately.  ID#: PEN413 Amethyst: One (1) prong set, round cabochon cut amethyst measuring approximately 9.9mm (diameter) x 5.3mm  Metal: 18k yellow gold (acid tested)  Dimensions: 27.2mm (with bail) x 13.9mm x 7.8mm  Weight: 2.9g No visible markings