Lapidaryforum.net
Let's Rock => Mineral Specimens => Topic started by: Kaljaia on December 03, 2016, 12:35:21 PM
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Another creek bed rock. Walked the length of the drainage but didn't see any more. There is a green semi-jasper in veins upstream, but nothing with that vivid blue color. It's a spray-paint turquoise blue. Tried some variations in lighting to give a good idea of the color.
I think the crystals are calcite and the blue appears to be a patina or a very thin layer between the cavities. Not solid enough to cut and I doubt the blue will show up on unweathered surfaces. But still an interesting display piece.
*Verdigris blue. That's the word I was looking for.
(https://68.media.tumblr.com/32eda1d5b70d1defc406b43f3a34605c/tumblr_ohmmazb2OO1spns93o1_1280.jpg)
(https://68.media.tumblr.com/6fba8e8d7ee6f9f095738a615df26d2f/tumblr_ohmmazb2OO1spns93o2_1280.jpg)
(https://68.media.tumblr.com/786a8c43e784f73bbca4008c4b237a8f/tumblr_ohmmazb2OO1spns93o3_1280.jpg)
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I was more wondering what was the rock on which it lies? Is that fossil or a hydrothermal formation?
If it had been from northern Mexico or south Arizona, my first guess would be something like aurichalcite, but I've never heard of that from that area. The blue could be an iron-based crust (something like melanterite) that have been found in north-central Oregon. Odd rock - and therefor fascinating.
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I was more wondering what was the rock on which it lies? Is that fossil or a hydrothermal formation?
If it had been from northern Mexico or south Arizona, my first guess would be something like aurichalcite, but I've never heard of that from that area. The blue could be an iron-based crust (something like melanterite) that have been found in north-central Oregon. Odd rock - and therefor fascinating.
Base rock in the drainage is volcanic (though there's fossil material within a 1 mile radius). Hydrothermal probably, though for extra fun a section of the Dalles-Canyon City highway ran right up the creek bed, so theoretically this rock could have been trucked in from anywhere in the mining districts of central Oregon, 1860-1870, and dropped along with a shovel, an ox shoe, several dozen cans and lots and lots of glass.
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There are lots of small hydrothermal copper zones around. People don't think of copper when you think of eastern Oregon but the sunstone even has copper crystals in it at times.
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There are lots of small hydrothermal copper zones around. People don't think of copper when you think of eastern Oregon but the sunstone even has copper crystals in it at times.
Yeah, I haven't found reports of it mined in the area (Mercury, trace gold, trace silver, and coal, yes, but not yet verification for copper mining) but there's streaks of teal and turquoise soil in road cuts and a lot of a bright blue patina in volcanic rock. Just not this bright, usually! Or soil, and crumbly, and weathered, so the moment you touch it it goes away. Lots of iron here too, and calcium. Annoying, chalky, make-your-water-taste-like-dust calcium. Some old appliances will have streaks this color blue on them, from copper that is no longer on the inside of the pipes. We're using a water softener that sequesters calcium now and more old pipes are starting to leak, because they were held together by the calcium deposits on the inside. A leak in a hot water pipe will make stalactites of calcium and verdigris.
I will try to get better pictures of the crystals in this rock. There's a faint orange layer of crystals behind the calcite or quartz, but they're tiny.