panamark
fully equipped rock polisher
Member since September 2012
Posts: 1,343
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Post by panamark on Aug 11, 2013 23:07:56 GMT -5
Maybe someone can ID these. Not awesome, but nonetheless maybe interesting. First, a rock that I brought home from Panama. It is about the size of a softball. It looked interesting and I wondered if it had promise inside so I lugged it through all the security checks at the airports. I am sure they hadn't seen that before, LOL. It is jet black and the "crystals?" are pure white, despite what the picture shows. Is this just basalt with some crystals in it? The material is quite hard and should polish nice. And luckily, I found quite a bit. The next two are stuff I found around here in Idaho. Maybe the left one is just our version of Puddingstone, LOL. The second is a wet slab I cut from an agate? of some sort.
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Post by vegasjames on Aug 11, 2013 23:40:36 GMT -5
The first is plagioclase cystals in basalt. I have a very similar piece with the large plagioclase crystals from here in Southern Nevada. The slower the crystals cooled the larger they became. The bottom left looks kind of like a lunar meteorite, such as this one www.lunarrock.com/meteorites/lunar/nwa5000.htmlv. Not likely though. If it were you could retire. The bottom right looks like a quartz.
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panamark
fully equipped rock polisher
Member since September 2012
Posts: 1,343
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Post by panamark on Aug 11, 2013 23:51:16 GMT -5
Yeah James, it kind looks like that one and I would love for it to be a meteorite, but afraid it is more of a terrestrial conglomerate. (BTW, the link has an extra "v" on end.)
I originally thought quartz, but I can find no crystal evidence, no matter how hard I look. Quite a bit more micro-crystalline but still not quite agate. Is there an intermediate stage?
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Post by vegasjames on Aug 12, 2013 1:46:54 GMT -5
Yes, I agree that the black and white rock is a conglomerate. The iron staining is a give-a-way that is it not lunar. Just saying it looked a lot like one. Mainly due to the angular fragments and color. Lunar meteorites can be difficult to distinguish from terrestrial rocks, which is why it is nearly impossible to even get a suspect lunar rock tested without a fusion crust.
Have you tested the hardness of the last rock? Could also be chalcedony.
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Deleted
Deleted Member
Member since January 1970
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Post by Deleted on Aug 12, 2013 3:13:47 GMT -5
You can do a search on "Chinese writing stone" for examples of the first piece used as gem material. As James said, it is feldspar xtls in basalt (the name for it is porphyritic basalt). The bottom-left looks like some sort of breccia (could again be feldspar in there). I've seen agate with the healed spiderweb fracturing from several locations, but a specific location isn't ringing any bells. Those can make some nice cab designs if well-healed.
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panamark
fully equipped rock polisher
Member since September 2012
Posts: 1,343
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Post by panamark on Aug 12, 2013 18:08:47 GMT -5
Thanks! I did find a lot on Chinese writing stone and it looks like some stuff with good possibilities! Yes, the bottom left one does look like a breccia and it is hard and will take a nice polish. Already is shiny from being rolled in a river. The bottom right one is as hard as agate for sure James. It gave the saw a good workout. And the fractures are well healed and the piece is very solid. When you hold it up to the light it looks like lightning running thru it. Will try some cabs.
Thanks all!
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Post by Pat on Aug 12, 2013 18:34:36 GMT -5
Your first one looks like Chinese Writing Rock. Used for cabs rather nicely!
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