Roman, 2nd century BC - 2nd century AD.
The only non Roman gem is the largest intaglio depicting a dolphin which dates to the 16th - 17th century AD.
The largest intaglio measures 2 x 2.3cm and the smallest intaglio measures 1 x 0.8cm.
The necklace measures approximately 18 inches / 45cm long.
The necklace is of recent manufacture in 18 carat gold, the total weight is 69.4 grams.