Antique Pink Cameo Necklace Shell or Angel Skin Coral Cameo Set in Rose Gold Filled Frame hotsell with Seed Pearl Accents 16 Inch Chain (D5)

Antique pink cameo necklace of shell or angel skin coral cameo set in rose gold filled frame with seed pearl accents on a 16 inch chain. It measures about 1 1/4 inches by 7/8 of an inch. There are no gold content marks on the metal , but it has weight and looks like it is gold filled. The cameo is carved nicely and is white and pale pink (closer in color to the 1st and 4th photos). It is either angel skin coral or some kind of shell. It looks very much like angel skin coral from other cameos I have seen. On the back of the cameo itself there is a roughly scratched 585. It is visible under magnification. I know it is the number for hotsell 14K gold but I don't understand why it would be scratched into the coral. I wonder if a previous owner had it tested and then marked the shell. I can see where the gold has worn off when I look at it under magnification. The chain is not marked either, but is at least gold filled. It is a very attractive cameo necklace and it is in very good condition.