Rock 03: these rocks are shit. But one can very clearly see how they were made. And that's one of the reasons why they are shit.

Rock 04: the texture on the left rock looks very rockishy, the right one is rather metallic...

Rock 05: left one I like, texturewise. Right one looks like it's from Unreal.

Rock 06: Left and middle look ok, texturewise. So that leaves four good textures for me - some aren't reddish-brown of course - but they look like rocks ate least.