These are all so pretty!
I'm more into fossils than crystals myself. The only crystals I find are small quartz pebbles (mostly around the creek) and chert (in the driveway gravel). I did find a decent-size chunk of quartzite once, though (about the size of my fist). Not rare by any means (similar, though usually smaller, stones are commonly used in landscaping), but I thought it was cool. I've heard that Native Americans used these stones like hammers when making weapons (such as arrowheads).
I also found this crazy-looking thing. I thought it had to be a fossil with that kind of pattern, but it's actually a siderite nodule. The "alligator skin" texture was apparently formed by a process called dewatering (when the shell of the nodule cracks and gel seeps out of it). Not sure how rare they are (I can't find much info on them), but I think I read somewhere that Native Americans would carry these stones around as talismans for "good medicine."
And even though I've already posted it in my fossil thread, I can't help but show-off my favorite find. Not my biggest or most-detailed fossil, but I longed to find an ammonite (the ancient shelled-squid that Omanyte was based on) ever since I discovered that we had fossils here. It was improbable since most of the local fossils are plants, but I just happened to notice this in the creek and thought... could it be!? So I had it looked at and it turned out to be a Goniatite, a small type of ammonite -- or ammonoid to be precise. Score!
Back to crystals though, I certainly wouldn't mind having a big ol' deep green emerald. Not only is it my birthstone, but I've been fascinated by shiny/metallic green things (like certain beetles) since I was a little kid. I have a class ring from middle school with an emerald in it, but I'm not sure if it's real.
