NevadaBill
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Post by NevadaBill on Mar 18, 2019 9:53:55 GMT -5
I came across this in some Nevada desert, float of what looks to be an older river bed (rounded assortment of larger rocks glued together by mud and gravel). My guess is Chalcedony, but I'm pretty new at rocks. I could be wrong. I have not come across something which looks more like the exoskeleton of something, rather than a rock though. I looks like a dragon head with a pearl in his mouth, to me. So I wonder how it might have been formed? Thank you to anyone who might know. [Edit] The pictures I took make it look pretty flat actually, but I would say it is about 2" inches across. Thx.
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Sabre52
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Me and my gal, Rosie
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Post by Sabre52 on Mar 18, 2019 10:06:07 GMT -5
That's example of a "Desert Rose" or Chalcedony Rose. They weather from volcanic rocks like basalt and Rhyolite in many desert locations. In situ they fill cracks and voids in the matrix. The silica usually comes from overlaying ash deposits or silica in the overlaying igneous matrix and the silica is deposited at fairly cool temperatures as the silica percolates down through the matrix and fills the voids. Very common to see those grape like botryoidal formations and some can get very fancy and actually look like roses. Whenever we'd go east around Needles, CA when I was a kid that was always a stop we made. Back in those days, you could pick up a bucketfull of chalcedony roses in half an hour right near the roads....Mel
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NevadaBill
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Member since January 2019
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Post by NevadaBill on Mar 18, 2019 10:36:24 GMT -5
Thanks Mel. I didn't expect such an interesting and scientific answer this quickly.
Yes, it was found only 1.5 hours north of Needles, next to a desert hill covered with all sorts of volcanic rock. The area saw all kinds of unusual volcanic activity, and the resulting ash from those volcanoes is reflected in much of the rocks here.
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Deleted
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Post by Deleted on Mar 18, 2019 10:49:32 GMT -5
looks like a dragon head with a pearl in his mouth, to me. Should be able to easily sell it with that description - does look like the skull of a dragon who managed to catch the flaming pearl. Certainly a powerful symbol throughout east Asia (though you aren't supposed to deface a dragon depiction).
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NevadaBill
fully equipped rock polisher
Member since January 2019
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Post by NevadaBill on Mar 18, 2019 18:18:25 GMT -5
looks like a dragon head with a pearl in his mouth, to me. Should be able to easily sell it with that description - does look like the skull of a dragon who managed to catch the flaming pearl. Certainly a powerful symbol throughout east Asia (though you aren't supposed to deface a dragon depiction). Thanks R2D. You sound knowledgeable for sure. My wife is from mainland China. She says that she wants to keep it. Likely for the same reason. It will probably sit on a table in the entry way next to a pair of large Jade Pixiu that I brought back from Beijing.
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RWA3006
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Member since March 2009
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Post by RWA3006 on Mar 19, 2019 21:05:49 GMT -5
That's example of a "Desert Rose" or Chalcedony Rose. They weather from volcanic rocks like basalt and Rhyolite in many desert locations. In situ they fill cracks and voids in the matrix. The silica usually comes from overlaying ash deposits or silica in the overlaying igneous matrix and the silica is deposited at fairly cool temperatures as the silica percolates down through the matrix and fills the voids. Very common to see those grape like botryoidal formations and some can get very fancy and actually look like roses. Whenever we'd go east around Needles, CA when I was a kid that was always a stop we made. Back in those days, you could pick up a bucketfull of chalcedony roses in half an hour right near the roads....Mel I'm pretty sure Mel called this one correctly. I've picked up a few buckets of roses in the Turtle Mountains also, and on some of them you can see the rhyolite, which is softer, hasn't finished weathering away from the chalcedony which is more durable.
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Post by vegasjames on Mar 20, 2019 0:44:12 GMT -5
Yes, it is chalcedony. Common around here as well. Does look like a dragon head. Cool find.
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NevadaBill
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Post by NevadaBill on Mar 20, 2019 10:14:44 GMT -5
That's example of a "Desert Rose" or Chalcedony Rose. They weather from volcanic rocks like basalt and Rhyolite in many desert locations. In situ they fill cracks and voids in the matrix. The silica usually comes from overlaying ash deposits or silica in the overlaying igneous matrix and the silica is deposited at fairly cool temperatures as the silica percolates down through the matrix and fills the voids. Very common to see those grape like botryoidal formations and some can get very fancy and actually look like roses. Whenever we'd go east around Needles, CA when I was a kid that was always a stop we made. Back in those days, you could pick up a bucketfull of chalcedony roses in half an hour right near the roads....Mel I'm pretty sure Mel called this one correctly. I've picked up a few buckets of roses in the Turtle Mountains also, and on some of them you can see the rhyolite, which is softer, hasn't finished weathering away from the chalcedony which is more durable. Thanks Randy. I will have to work my way further South then some time. I have some GPS coordinates on a couple of spots out by where you mention, which might have some Jasper, Agates or other neat stuff close by. I appreciate both of you for taking the time to mention the Needles location.
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RWA3006
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Post by RWA3006 on Mar 20, 2019 16:53:22 GMT -5
PM me when you go and I'll give you a location or two. I used to go camping down there in December and January. Made for a pleasant trip.
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pocketfullarocks
having dreams about rocks
I love being a rock and mineral nerd!
Member since March 2019
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Post by pocketfullarocks on Mar 21, 2019 22:15:34 GMT -5
That is a very cool find! (And I am learning so much reading all this fabulous identification information!) I have to remark that Nature also amazes me in that this rock in California reminds me in form so much of Florida's claim to fame in the mineral world - Agatized Coral. The remineralization of these coral sounds and looks something like explained by Sabre52 for this chalcedony. (an internet borrowed photo of a slice of agatized coral):
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NevadaBill
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Post by NevadaBill on Mar 24, 2019 15:13:26 GMT -5
PM me when you go and I'll give you a location or two. I used to go camping down there in December and January. Made for a pleasant trip. Thanks for offering Randy! I will definitely do that.
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