Authentic Stigbert 18k Gold Amethyst & Chrysophase Pierced Earrings. Fully signed: STIGBERT HE (for Herbert Engelbert) 18k Sweden C9. The cabochon amethyst measures 5.96mm and the brilliant green chrysophase measures 3.35mm. Stunning and very rare, these earrings are in excellent condition.. Each earring measures 23.7mm X 18.55mm.