This seal shows two acrobats performing backflips. The stone is blue chalcedony and it was found near Knossos.
Bibliography
Evans, Arthur. 1935. The Palace of Minos at Knossos, IV, p. 501-503, fig. 443
Myres, John (ed.). 1936. British Archaeological Discoveries in Greece and Crete 1886-1936, p. 28
Hughes-Brock, Helen and Boardman, John. 2009. Corpus of Minoan and Mycenaean Seals VI: Oxford, the Ashmolean Museum, no. 184