Argent Sterling Teinté Calcédoine et Marcassite Hexagone Boucles D'OreillesAbout This Item A deep green chalcedony hexagon, surrounded by a marcasite halo with a single gemstone embellishment in the centre of each stud. These earrings have a post and butterfly, and are suitable for pierced ears only. Gemstone Information Chalcedony is suggested to be one of the earliest materials that man used, noted as being used in the city walls of New Jerusalem. Chalcedony is often used in carvings and tools as well as jewellery.