Infact I just put some samples of what is selling I Iran Bazar as what you mentioned. Surely most of them are not shell at all and some green or grey Stones comes from Afghanistan. I have seen some real ancient shell ones but as I was not interested, in them , I gave them free to my friends. Till I found they cost alot in Persian golf. We are here to discuss about beads and I think you are one those that we can trust and accept scientific reasons.
Best regards

Ali