A thread like this should become an all-time classic. My contribution, sorry don't have photos:
1. When I was a kid my grandfather gave me a small hand specimen of an ultramafic from the Klamath (Trinity?) area that had visible platinum in it. He wanted me to perform an assay on it, but that was both beyond my skill and there were more exciting things I could do with my chemistry set anyhow. Somewhere along the line I gave the rock away, but I still remember it vividly.
2. I've posted here on actinolite. I like actinolite because although it's not common, it's very distinctive and easy to recognize when you see it.
3. Gotta love gold, it's the industry in which I earn my living.
4. At mineral shows, I drool over darn near everything, but the schiller of labradorite and the unique color and texture of turquoise always snag me for yet another look. Optical funny stuff like double-refracting calcite and "television stone" selenite are fun, too.
5. But, my day job is metal detectors, and what matters there is rocks with interesting magnetic properties. So my actual rock collection is mostly the ugliest stupid rocks anyone can imagine: magnetite, pyroxenite, goethite, limonite, siderite, hematite, and rocks and soils that contain maghemite (which is never found as "specimens"). My favoritist rocks on the job are the ones that have the highest magnetic loss angle, and you can't tell by looking at the rock what that will be other than that it will usually be reddish (but most reddish rocks have a relatively low magnetic loss angle). Someday I'll stumble across a silicized paleox and have to explain to the vendor what he or she actually has. After having purchased the best specimen, of course.
love this rock
this is by far my biggest one, but I have about 100 or so of these types of rocks in my collection
