WOW antique shell Cameo, large, floral & filagree setting, Victorian, Downton !

This is a very beautiful carved shell CAMEO set into a silver filigree base with tiny flower accents. It has a straight pin across the back as well as a loop , so it can be used as a pendant. There is no silver content or manufactures marking on this. I believe it is Victorian. It is in excellent condition. Please see pictures for measurements and close-ups! Wonderful for your collection or a fabulous gift! Thank you so much for looking.