help me to find out about these big and old seashells

[enel]

Thank you Mike!
That's it <img src="images/smiley/smile.gif" alt="" border="0" />
And they were partially covered with the hard crust (that is shown on a lot of images) it comes off quite easy ... I've cleaned couple of them and they're beautiful!

I have not finished them with anything yet since they seem to have quite fragile top layer. Should I use mineral oil or clear coat them? I'll see what I can find on the internet also ...

Thank you sincerely