A Greek gold bracelet dating to circa 300 BC has been estimated at $150,000-250,000 in the run-up to Christie's Ancient Jewellery sale.
The auction will take place in New York on December 13.
The Hellenistic period bracelet is formed of a hollow hoop decorated with small birds and a representation of the god Pan. A Herakles knot at the centre is centred with a die-formed lion.
The Hellenistic period spans the time in Greece between the death of Alexander the Great in 323 BC and Rome's victory at the Battle of Actium in 31 BC. It is regarded as a time of decadence in contrast to the glories of the Grecian classical era.
The rise in affluence in Greece brought a demand for high quality jewellery, leading to the development of complex designs - including the Herakles knot.
A Greek gold and carnelian ring dating to 330-300 BC is valued at $120,000-180,000.
It features a depiction of an older Herakles engraved in profile on the bezel, a design that retained its popularity well into the third century AD.
Similar examples, one found in Taranto and the other in Avola - both in Italy - are featured in the British Museum.
A Roman Sardonyx cameo from the first century AD is estimated at $100,000-150,000.
The piece displays a virtuosic level of carving, with the artist exploiting the natural banding of the stone to create a three dimensional bacchante, or priest of Bacchus, in profile.
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