Can gravel Damage fins?

I have a cory that lately seems to spend most of the time swimming in the middle of the tank. I noticed his towards the front bottom (sorry do not know the proper name) and his tail fin towards the bottom seem to be a bit worn. Is the colored gravel I have in the bottom of my tank cause this. I did not notice this when he spent most of his day on the bottom. The parameters on my tank are all '0' and other thatn the fin wear he seems to be fine.

For a little more info, it is Estes decorative stone in my aquarium so it has edges, it is not as smooth as pebbles.

Also, if it is not wear damage what could it be??

If not the gravel, do you know what could cause it. I have not noticed any of the other fish acting aggresively towards him. My other cory never want to come off the bottom exept for the occasional quick dash to the top so I cannot really see if his fins look the same.

Tank mates are 2 guppies (they spend all day harrassing each other, I don't think they know there are other fish in tank), 6 neons, 5 Harlequin rasboras, 1 otto, 4 ghost shrimp, 2 blue rams, and another albino cory. I had heard that rams can sometimes have issues with cories but I have never seen any. I have watched them for several hours and usually the rams are tucked away in the plant and when they come out they just tend to chase each other.