Not too Sure on the Superglue, but check out your lfs for rock bonding compounds. I can't recall the name or manuf. of the stuff, but it's basically like a epoxy clay compound that is used for bonding live rock and landscape rock together in a tank. Just DON'T go to a Hardware and buy epoxy. I purchased this rock compound at my lfs and it works great. I think I paid $4 or $5 dollars for it and it was enough to do 120lbs of rock. You don't need too much on a rock and you can't even notice it on the rocks, it blends in great.