Is this event done in the same format as fossils is (was)? ie: will it still be a station event, usually with one or two IDs per station and a few questions about the properties/ uses/ formation of the rock or mineral in question? I am probably getting this event next year, and am trying to get a head start.
Pretty much - trial rules are online, with a list that will probably be changed little.
So is it like... definite that you'll get a field guide AND a three-ring binder? (That's what it says in the Trial Event Rules, but I don't know if that's going to be changed anytime soon.)
Also, binders can be any size, right? So technically (I'm not really going to do this), you could bring in like, a 5 inch binder? Or is it like, only 1 inch or some other size restriction?
If it's the same as Fossils (which it probably will be), there's no size restriction on the binder.
The question is, though, why would you want a 5 inch binder in the first place> You really don't need that much information, and it just becomes a pain to find everything you need.
I've done the event tons of times, so here's my experience from the event:
ID is by far the most important thing. Once you ID the sample, most of the information should be in your binder. It's a bit different from Fossils though in that not every sample can be identified on sight. You're gonna have to test hardness and streak at least to be completely sure, unless you've seen so many samples that you can do it without that. Most minerals can be identified with no problem, though you have some pairs of minerals that really resemble each other (epidote and olivine, celestite and barite, bornite and chalcopyrite, etc.).
Tip: in Earth Science class, teachers tell you that color is the worst thing to use to identify. From my experience, it's actually much more useful than any of the others, since you can instantly narrow it down or identify it on sight.
Apart from the ID and property-based questions (hardness, uses, chemical formula,etc.), you'll also see questions on areas of rock and mineral formation, Bowen's Reaction Series (for division C), and you might be asked to find the hardness and/or density of a sample that isn't on your list. They don't go very in depth in mineralogy; I've taken Mineralogy in college and the event barely scratches the surface (which is fine by me, because that would be a bit much to expect kids to learn).
Hope this helps. Rocks and Minerals is my favorite event ever, even more than Fossils. =)