A large Shell Cameo of the Goddess  of youth ,Hebe ( Ganymeda) feeding the eagle. The latter is generally considered to be a personification of the god Zeus.
A expert carving . These were originally collected as souvenirs in Italy , as part of the Grand Tour. They proved immensely popular with the English and in the Victorian period were imported in bulk, unmounted , to feed the English demand.
This looks to be an Italian shell cameo in an English, 15ct gold, tested, mount. The deep gold mount curves to mirror the undulating curve of the shell. This style of mount was in vogue during the 1860 -1880's. 
The quality of the carving of a cameo is judged by the crispness and detail. Here you can see every feather of the eagles wings and the folds of Hebe's gown are a delight. 
The C catch and the hanging ring for use as a pendant are original.
Size 2.4 x 1.9 inch
Weight 15.37 gms
Faults  The Gold pin has been replaced by a silver pin 
Delivered Boxed , tracked, insured.