A fortified thinset mortar (don't get the pre-mixed kind) should work. Read the label on it to make sure it will adhere to glass. If you decide to go that way, make sure you get the white thinset - the grey could show through.

Hi vettupete....
Thanks for the suggestion. How thick can thin set go on without some sort of mesh or something? Like for example could I use it to fill in some of the mortar joints in between some stones if I wanted to?
Thanks
Kathleen

It can be pretty thick especially if it's just in isolated areas like mortar joints. If the stone you have is somewhat irregular, you might want to first apply a coat of the thinset to fill in the joints and even out the surface. This would probably be advisable in your case since it sounds like you want to use a lot of small pieces of tile and glass. This way you'll have a level surface to work off of and will only need a thin coat of additional thinset to hold them.

Hi again, sorry for the mis-spell on your name........

Thanks so much for your help!! I am fearful somewhat of thinset................ seems so .............. permanent; lol
I know I want to work w/the irreg surface but want the freedom to be able to maintain or cast a notion .......... if you know what I mean. So, knowing that I can fill a joint to carry a theme helps alot! Thanks again
Kathleen

Thinset is pretty easy to work with and it grips quickly but the tiles can slip until it dries so make sure you support them with spacers, etc. The other thing you need to be careful about is that it's very hard to get off surfaces once it dries, so clean up as you work is important. Good luck and I'd love to see a picture of what you do. My e-mail address is on my profile.