They look like some sort of mineral gems. Anyway, this is indeed a fourth (next to last) instar male nymph of an Orange-winged Grasshopper.

As for where to put it. If you don't know for sure, ID Request is fine. After-all that's why it's there. However, if you know which group it belongs to (such as order Orthoptera, or family Acrididae), that's fine as well. Best not to put it anywhere you'r not sure of though.

Getting back to the hopper. Yes, the pronotum is the "saddle"-like or "collar"-like part behind the head. The crest (shortened from median crest) is the ridge that runs right down the middle of the back, and the notch (there is one obvious one) is very visible just in front of the middle of the crest (there is a tiny bit of an offset there in this individual). It's usually easier to see in profile than from above, though having both views often helps. Both of your photos are basically from above (too much so to see the "crest" in profile). Also, sometimes the distinction between one or two notches is a bit subjective, though usually it's fairly clear.

Moved from Grasshoppers, Crickets, Katydids.

Moved from ID Request.