Rectangular gem with dancing satyr

Dark purple glass. Intaglio. Rectangular with bezeled sides, broken at top and bottom; bubbles and holes throughout surface. The satyr moves to the left. His head is thrown back sharply, in a manner that over-extends the neck and thrusts the chin upwards. His right leg is bent back and very shallowly carved. He holds a staff (thyrsus) in his extended left arm; and a panther pelt is draped over his right arm. Very finely modeled.