IRAN, CIRCA 3RD-5TH CENTURY A.D.

It has also been suggested that the engraving on this gem might be a portrait of the Parthian King Pacorus II (AD 78-110), based on depictions of the ruler on coins from his reign. Unfortunately there are virtually no surviving seal stones ascribed to the Parthian period. A.D.H. Bivar, in Catalogue of the Western Asiatic Seals in the British Museum. Stamp Seals II: The Sassanian Dynasty, London, 1969, says that “The question is complicated by the uncertainties existing as to the glyptic of the preceding Parthian period, and the doubts at one time current as to whether Parthian seal-engraving existed at all". However, Pliny the Younger in a letter addressed to Trajan around AD 110 (Plin. Ep. 10.74.1–3) informs us of an interesting fact: Decebalus, the last King of Dacia, sent as a gift a slave called Callidromus to Pacorus II, King of Parthia. After many years Callidromus managed to escape carrying with him an engraved gem showing the portrait of his former master Pacorus. Having unfortunately lost the gem when he presented himself to Pliny, he was unable to prove his affiliation to Trajan, see M. Rahim Shayegan 'The End of the Parthian Arsacid Empire' in The End of Empires, Wiesbaden, 2022, pp. 213–247.
However, given the lack of an existing corpus of Parthian intaglios to support this fascinating proposition, it is more cautious to assume that the profile bust on the present ringstone depicts a member of the Sasanian ruling family.