Beanz

Began my journey in finding copper ore (Homo Sapien run). Simple question: do ores not show up in blocks until you've prospected the area? I ask because of a recent event when caving, and not seeing copper until after I had prospected the area and seeing copper appear in a location I had thought I seen to contain no copper (i.e. the rock blocks I saw previously not having copper, suddenly showed copper). I also saw the same case from a youtube video, where they explained how one finds copper (harder to tell if its the case due to camera angles not showing the blocks previous state prior to using a prospecting mode).

VanillaPlus WorldGen (I haven't used it yet, but by the looks of it this might be what you're looking for.) Otherwise you might want to invest in a few shovels, and maybe a pickaxe.