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Post by Cher on Oct 12, 2004 13:13:24 GMT -5
Dang this stuff is really hard to get a picture that shows good color, this is the best I can do. Here was the first pic that shows how you can see through it in the thinner areas. Look close and you can see the lighter green colors. The rest of it is almost a bluish green. Thanks for looking, any ideas? Cher   |
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Post by puppie96 on Oct 13, 2004 3:21:40 GMT -5
Hi Cher, I see this has had 39 hits and no responses. Danged if I know, I'm the one that's trying to learn rock ID and I don't trust any of my opinions. It looks similar to stuff I've got, but I don't think your photos have captured the green yet. Now and then I've got intensely green stuff showing up. I've got a big chunk of lightish green translucent stone with speckles of dark emerald green here and there -- it looks for all the world as if bits of powdered dye were in there. It's not a drab or olive green, I'm thinking it's green aventurine, however, I look at photos of green quartz and then I don't know. That's my life in the rock ID area.
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deepsouth
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He who rocks last rocks best
Member since January 2004
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Post by deepsouth on Oct 13, 2004 5:07:46 GMT -5
Serpentine does come in different shades of green. I will have to take some shots of the 3 pieces I have and show them on this page
Jack
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Post by Cher on Oct 13, 2004 10:15:18 GMT -5
This piece is definitely going on the shelf to be slabbed if/when I get a saw. There's no way I'm going to whack this with a hammer. It has some fractures in it around the edges but the main body of the rock looks really solid.
I've got some green adventurine, this looks nothing like that at all. Looking at the edge of it (like in the first picture) I just know this will be totally awesome slabbed. I wish there was a way to try and get it identified but I'd never send it anywhere ... I'd be afraid I'd never get it back.
Jack I'd love to see the serpentine, take some pics please.
Cher
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AgateHunter
starting to spend too much on rocks
LAKE SUPERIOR AGATE Minnesota State Gemstone
Member since September 2004
Posts: 107
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Post by AgateHunter on Oct 13, 2004 21:02:45 GMT -5
Looking at your pic and then one in my book, National Audubon Society, First Field Guide, Rocks and Minerals, Page 59, It looks like a Sapphire. It says, all gem-quality corundum that is not ruby is called sapphire. Commonly seen as a blue stone, sapphire can also be pink, green, violet, grey and yellow. Your pic and the one on the book look a lot alike.  |
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Post by Cher on Oct 13, 2004 21:16:26 GMT -5
I have never heard of Sapphires being found in Minnesota, have you? I've never been to a sapphire mine so I don't know how they are generally found. I mean like do you have to dig in caves for them or are what? Very curious, does anyone have any idea where a person could take it to be checked or tested?
Cher
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AgateHunter
starting to spend too much on rocks
LAKE SUPERIOR AGATE Minnesota State Gemstone
Member since September 2004
Posts: 107
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Post by AgateHunter on Oct 13, 2004 21:29:00 GMT -5
My books says, Environment: Corundem forms in igneous rocks called pegmatites that occur with nepheline syenites, and with muscovite, almandine, and quartz in schist and gneiss. Most corundum is mined from sediments.
I do not know what all that means.
Who knows in Minnesota! All of our rock is a mix, thanks to the Glaciers.
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Post by Cher on Oct 13, 2004 21:54:28 GMT -5
Hmmmm I might have to go back there with a shovel. LOL Be pretty neat if I could find more. This was a huge gravel pit we were at, never saw a thing like it anywhere else there either ... but that's doesn't mean there's not more there. Thanks, that's very interesting.
Cher
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Post by puppie96 on Oct 14, 2004 0:28:56 GMT -5
Cher, I've read a lot about sapphire/ruby and although your state obviously isn't one of the mining areas, corundum does show up occasionally in other areas, and as you said glacial soils are a grab bag.
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rollingstone
starting to spend too much on rocks
Member since July 2009
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Post by rollingstone on Oct 14, 2004 1:30:25 GMT -5
Do a Mohs test on it, as that might help narrow things down. Can it scratch or be scratched by your fingernail, a copper penny, a steel file, a piece of glass, a piece of quartz?
If it is sapphire, it would scratch all of the above, and be scratched by none of the above.
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Post by Cher on Oct 14, 2004 13:47:06 GMT -5
I didn't have any glass to scratch so took the closest thing I had to it ... a piece of polished quartz. Yes, it definitely will scratch quartz.  I got this pic that shows the colors a little better.  I took a piece of broken quartz and rubbed it against the side of the rock, the quartz (on the outside that had been exposed to weathering) just pulverized to powder. But, on the other size that was rough from where I had cracked it, when I scraped this piece across it, there were sparks. Could this be some kind of flint? On the back side, there's only one small circle of the lighter green. Pretty shiney for just coming out of a gravel pit.  Cher |
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rollingstone
starting to spend too much on rocks
Member since July 2009
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Post by rollingstone on Oct 14, 2004 16:55:49 GMT -5
Interesting. So your rock must be about as hard as quartz or harder. Did a sharp piece of quartz manage to scratch the mystery stone or not? If I recall correctly, a rock can scratch something up to 0.5 Mohs unit harder than itself. So if quartz can't scratch your stone then it falls into a select group of very hard minerals. And if quartz can scratch it, then it must be some variety of quartz, which can probably be narrowed down by the colour. My thoughts anyway.
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Post by Cher on Oct 14, 2004 17:53:00 GMT -5
No, the quartz couldn't scratch it. It (the quartz) just crumbled with I tried it.
Cher
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rollingstone
starting to spend too much on rocks
Member since July 2009
Posts: 236
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Post by rollingstone on Oct 14, 2004 19:07:29 GMT -5
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Post by cookie3rocks on Oct 14, 2004 19:19:17 GMT -5
Hmmm, that's some hard stuff! I went through a corudum stage a while back (went mining for it at one point) and the thing about corundum is it allways takes on a hexagonal shape. Even if part of it is broken away, you can see definate flats around it. I don't see that with this stone. Hmmm  cookie |
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Post by Cher on Oct 14, 2004 20:14:26 GMT -5
Thanks for all your help and thoughts. Sure would be nice if there was some place I could take it to have it identified. I'll go through that link and see if I can find some things that I think match it.
Cher
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deepsouth
fully equipped rock polisher
He who rocks last rocks best
Member since January 2004
Posts: 1,256
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Post by deepsouth on Oct 15, 2004 2:39:28 GMT -5
Hi Cher , I am a bit slow with the foto, but that garden of ours is very big and spring needs all hands on deck.  I hope this helps you in identifying what you have. Jack |
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deepsouth
fully equipped rock polisher
He who rocks last rocks best
Member since January 2004
Posts: 1,256
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Post by deepsouth on Oct 15, 2004 2:40:53 GMT -5
Oops , I forgot to mention that this is the serpentine I told you about
have fun
jack
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