New update, but no pictures. Sorry.
Anyway, I started to detect ammonia in the tank even though I hadn't started cycling yet. My friend and I brainstormed where the ammonia was coming from and decided that the small amount of ammonia was probably coming from the old filter I got with the tank, since the only other thing in the tank was sand and I had already tested that. The filter had lots of algae film on it from the previous owners, and I was just too lazy to clean it before starting it. So since there was already a small amount of ammonia in the tank, I decided to start cycling! I'm doing a fish-less cycle on this tank, and right now I have a thin sock filled with leftover fish food (bloodworms) in it. I'm already noticing a rise in ammonia, so I guess that's going well.
I've tested all the rocks with one of the corrosive API test kit solutions and none fizzled, so I fairly sure they are safe to use. I'm going to wash all the dirt off them, then let them sock for 24 hours before adding them to the tank. I've decided that siliconing them together would be a mistake, as they already fit together rather well and I would like to be able to change the rock formations in the future.
More updates soon!