Glass Sea Shell - Cia Glass - Austin, Texas???

Don't remember where I picked up this shell, but I can't imagine I paid all that much for it. While I have a lot of smaller pieces/paperweights, they have never been a focus for my collection, so I usually only get them if I find a deal.

This one is a simple, yet beautiful form of a shell. There is a mark on the inside of the open part of the shell where it appears the piece wall "pulled" and formed against a mold (which is how I assume it was made). It is marked on the very tip of the piece with "Cia 07" which means nothing to me. I found some references to it as "Cia Glass" possibly being an Austin, Texas based glass company - and I have been to Austin...