Opposite to the Medusa medallion, at the back of the necklace, is a small, very finely worked pendant in the form of a bust of Isis. Isis can be identified by the usual attributes of the crown, locks, and knot. The addition of this pendant was believed to have imbued this necklace with double the protection for its wearer, with Medusa in front and Isis at back.

During the Republic, Romans shunned the opulent display of jewellery. Years later, as the Empire was established, vast amounts of gold and a wide array of luxury items poured into Rome from Greece, Asia Minor, and Egypt. Taste now changed, and it became fashionable to wear sumptuous jewellery. At first, the citizens of Imperial Rome preferred jewellery that exhibited very fine workmanship. But by the 2nd century AD, they favoured eye-catching ornaments made from thin sheet gold, and richly embellished with coloured stones and polychrome glass-paste settings.