Adorable Ouroboros ring, snake eating his own tail, representing birth, death and renewal and eternal love.
He has the stylised  duck face of the earlier snakes, with engraved scales and facial markings, and engraved ornamental eyes, very similar infact to the matching earrings from the same period. 
The head is set with a rather lovely Opal but pretty sure it would have originally been a garnet. 
The inner ring is engraved Jiulius J - I think! It is very worn down.
The back has cut out scales that contain hair but I can easily remove that for you if you wish. 
The ring is a size 7.5 and cannot be sized 
Weighs - 1.8g
European circa 1830 - 40 
Good antique condition
15 carat gold