The obverse is carved with the serpentine figure of Chnoubis with profile radiate lion head and tail in double coil. The reverse is inscribed XNOV_MIC, (a variant spelling Chnoumis), and IAW (another magical name), around the device for Chnoubis of a bar crossed with three S-shaped serpents. Around the edge of the intaglio is a further inscription. The gem is set in a Victorian period gold ring.
UK private collection, South-West England, by descent through the family. The ring was set in a gold ring in the 19th century
Magical or Gnostic Gems were used mainly in Hellenised Egyptian Alexandria. They combined Egyptian, Classical, Jewish and Christian symbols concerned with the protection of the owner and the elevation of his soul from the physical to the spiritual. The inscriptions are very often composed of voces magicae, or magical words and names combined to invoke a deity or group of supernatural entities.
This particular gem is designed to invoke Chnoubis and likely had some kind of therapeutic function. Chnoubis was a solar deity (the radiate lion head), with a chthonic element (the serpentine body) and it is likely that Chnoubis symbolised both the Nile and its flooding. The bar crossed with three S-shaped serpents is the astronomical sign for the first of the thirty-six decans, which coincided with the time of the Inundation.
For similar examples, cf. S. Michel, Die Magischen Gemmen. Zu Bildern und Zauberformeln auf geschnittenen Steinen der Antike und Neuzeit, Berlin, 2004. Also M. Henig, Classical Gems, Ancient and Modern Intaglios and Cameos in the Fitzwilliam Museum, Cambridge, 1994, nos. 500-502.