I agree that it might crack the glass, and will scratch it up pretty easily too. Mine gets very heavy, and the instructions tell me to always Lift it to put it on a burner, because if you slide it, it will damage your stove (and they were talking about one with gas burners).
That said, you will Love pressure canning!! For years my MIL or husband would do the actual process of it, I'd do the cooking of the sauce and prep the jars, fill the jars, etc. but they would do the actual pressure canning. I finally wanted to learn how to do it myself, and although the steps are Important...it is easy too! You will get a system down and if you stick to it, really it's quite easy.
Have fun and don't be intimidated by it!