antique small coro Cameo ear rings question

by Michelle
(Orrville, Ohio, U>S>A>)

unfortunately i have not got a photo to upload. this particular set of Coro Cameo ear rings has me a bit baffled. They are screw type back unpierced and are hallmarked Coro on back, the size from top to bottom is 2.0cm and 1.5cm across center. the profile is left, she seems young with fine features a large

(long) nose and protruding chin. the hair seems to be long but pulled up and hanging down. the neck is long.

The stone behind the portrait is very pale pink and has a sort of pearly esscence to it.The portrait carving is of a very light hue as well almost an ivory color, but without the shimmer of the stone behind. the match is different than the first of the young fine featured girl but seems to be the same woman, she seems to be a bit older and heavier can this just be a hand carving error? or was this done purposely?

they are hand carved. I would like to know are they of any worth, and what type of stone etc. they may be carved from. i would appreciate any information you could share. Thank You for you're time.
Regards Michelle Swinderman