This very large pendant consists of an onyx cameo in a gold setting. The cameo shows Dionysus, the god of wine, carrying a thyrsus and accompanied by a panther, as he discovers a dejected Ariadne. She had helped the hero Theseus kill the Minotaur but he then abandoned her on the island of Naxos on his way back to Athens. Dionysus finds her there and makes her his wife. A small figure of Eros, the god of love, stands beside Dionysus.
Although the pendant shows a classical subject, it is not ancient Greek or Roman but rather a Neo-classical gem made in the 17th or 18th century in imitation of an ancient gem. The pendant was collected in the 19th century by the eccentric Maxwell Sommerville, who gave his extensive gem collection, which includes both ancient and modern examples, to the Museum.
For the Sommerville gem collection, see Dietrich Berges, “Hidden Treasures from the Vault: Engraved Gems from the Maxwell Sommerville Collection” http://www.penn.museum/documents/publications/expedition/pdfs/41-1/hidden.pdf
Penn Museum Object #29-128-1358.
See this and other objects like it on Penn Museum’s Online Collection Database