Gorilla glass is tough, but definitely not unbreakable or unscratchable. Drop it on the corner of the tablet and the physics are just too much, just like dropping it facedown on concrete or aggregate is going to scratch it.
I would call Professional Satellite Repair in PA., you can find their number on the web. I know they do a pretty good business on iPad repair, I would guess they can repair or source your tablet. That all being said, unless this is something you have experience in, I think you should have it done professionally.
Yes it does have Gorilla glass and scratch resistance is a function of surface hardness. As a general rule, the harder an object the more brittle it becomes.