Later Roman Mottled Jasper "Magical" Gemstone

carved in intaglio with an image of the serpent Chnoubis, the coils of the snake interspersed with a Greek inscription.
2nd - 4th Centuries AD, Eastern Empire
Height: 18 mm. (0 3/4 in.)
Width: 19.8 mm (0 13/16 in.)
ex: a private American collection.
#5395
Published:
Antiquarium Ltd.; Ancient Treasures XIV (New York, 2016) p.34
Comparanda:
Michel, Simone ; Die Magischen Gemmen im Britischen Museum v.1-2 (London, 2001) pp.193-195, no.304