Cameo Collecting - Im new at this!

by TONI
(Grand Rapids,Mi)

I'm just starting to collect Cameos. I bought about 7 of them at a thrift store. All of them are shell Cameos with 4 of them being Sardonyx cameos.

Ok, here's my question, 2 of my Cameos have no signatures anywhere on them. I have searched them over a million times and have found nothing. I took them to the gold and silver store they are copper and zinc, both are 1 1/4 length and an 1 inch wide. I just don't know what to make of them. I did take them to the jewelry store as I wanted to make sure they were indeed shell Cameos. How does one put a date on these. Like I said I'm new at this collecting Cameos.