I guess I should have said yes, there are ways to glue it LOL - like glenm says, but baking with it is another issue! I can't imagine tasting a nice flakey croissant then that big "bang" taste of epoxy glue! :D
Look at the positive - you now have 2 stones!
glennm - too bad royal icing won't hold up in the oven - that would surely keep it together if it did! LOL