Back again. I've found, made, and modified a couple of the resources I used, and passed the class with a decent B-.
I'm popping in to say that going on a field course of some kind was a very helpful thing. It taught me to generalize more and stop caring very much. Things are very iffy a built around a very guesswork-based framework, so this field course really helped me speed up my IDing.
I'd suggest people go through google to do a bunch of searching, make a big file of information from multiple sources (since some sources disagree with each other on where the barriers are for different rock and mineral types are), and ask your TAs, Professors, and possibly colleagues for what they use.
I had a bunch of my stuff printed out and stapled together into a reference sheet, with some more reference stuff bound in a duotang.
I'm going to try to make it a project to bind all my stuff into one duotang, but I'd need to go over and remake basically every bit of reference info I have. That'll be a bit of an adventure, and I've even lost most of the sources, but lots of the things I've found used the same sources without credit, so I think that won't be too much of an issue.