During last week’s discussion of the Tucson snowfall, mention was made of another special event there that’s worth the wait, the annual Tucson Gem & Mineral Show. What with dopers generally being a well-travelled and scientifically inquisitive lot, it would come as no surprise to learn they’ve acquired some nice specimins at this and other shows, in rock shops or just picked up some significant pieces over the years. So here’s a chance to share what graces your shelves and mantles with the rest of us. Show us what it is you’ve collected and, if possible, where it came from… Gems and Minerals of the Straight Dope.
If anyone is interested we can maybe start a separate one for fossils and another for historic artifacts (arrowheads, pottery shards, etc). Just let me know if that sounds good or, if you’re willing, start one yourself.
My favorites are Lapis and opals. One of our bucket list vacations is opal mining in Nevada - Peacock mine has a campground and caters to vacationers mining.
mrAru has a boulder of desert jade[properly serpentine] lurking on a friends farm in Kerman CA, they scrounged it up on a rockhounding vacation they did together back in the early 80s. His stepfather Frank was from Ajo[home of the worlds largest open pit copper mine and source area for many neat Cu based minerals] and he gave Rob his liking for desert rambles for interesting rocks. I will have to have him find his box o’rocks in the barn, but I know he has a lovely fist sized hunk of amethyst, several large hunks of raw amber, and a firewood sized log of petrified wood that he has earmarked for projects.
I have a very small collection of minerals that I’ve collected over the years, just by happenstance. A river stone with purple and grey stripes - obviously sedimentary, but pretty colors. A couple of fossils I found in gravel driveways - both clams. Another sedimentary rock with a crystalline texture. I’ve also got a 5 mm aquamarine cabochon a distant cousin gave me.
I wouldn’t mind getting my hands on an ammonite fossil or some of the flashier minerals out there.
Mr. Ko and I have been going to the Tucson Gem and Mineral Show for almost 30 years. Since we already have a house full of rocks, crystals, petrified wood and fossils, when we go now, I just take pictures. I wish I could identify all these for you, like lieu did, but I’m just a gawk and click sort of dilettante.
One of the most inexplicable rocks I’ve found were these that came from our ranch 50 miles east of Walsenburg, CO. I was exploring some shale hills and saw a 4 foot wide mass of buff material, the smaller rock in the picture, embedded in the grey shale. It has cone-in-cone structures throughout. In the middle was the larger rock type in the picture, very indurated and at the very center were two pieces that fit together like a large clamshell, probably a foot across and lined with the red and gold quartz. The very center was open, making it look like a large clam geode. Now I don’t think it was actually derived from a clam but that describes its shape best. I found at least 5 more of these complex objects, each about another quarter mile down the shale hill outcrop. I’m sure we have hundreds all told.
I’ve done some research on the formation, plus asked around with a lot of geologist co-workers (I’m a Pet. Geo.) but as of yet the cause is a mystery to me and everyone else.