is this real and what is it worth

by megan
(kent)

hi my great gran left me this pair of cameo earrings and a cameo pendant in her will and i was just wondering if it is real amd what it is worth.They all have the same lady on them but no one is exactly the same the earrings have a mark on the back but i can not make out what it says and the pendant also has a mark on the the back that says R.g i would be grateful if anyone could help thanks megan