Antique Hand carved cameo pendant

Real hand crafted Shell cameo with filigree bottom. Marked Dan Dell 12k gf. I have had this for 30 years and got it from my mom. Measures about 1 " drop by 1/2 wide. Very pretty piece. It has not been worn much, but does show some age. Please see pics. My skin is very sensitive and I never had a problem with it.