ericabelle
spending too much on rocks
Instagram acct: @erica_shoots_everything
Member since April 2021
Posts: 482
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Post by ericabelle on Oct 9, 2022 11:55:50 GMT -5
Here is another rock I can't ID that was in the huge lot of rocks I bought. They are so pretty, with layers of red, white and yellow-tan. Every layer is fairly soft. I can scratch them with a stainless steel nail, but I have to push really hard. (I know, I really need a mohs kit!) The red and white layers are the hardest, and the yellowish-tan is a little softer. Can you tell me what they are and how best to show off their colors? I don't know if they are too soft to take a polish or not. I'm showing these rocks wet because they look really plain when dry. This is the pile - they range in size from 3 inches across to 7 inches across.
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ericabelle
spending too much on rocks
Instagram acct: @erica_shoots_everything
Member since April 2021
Posts: 482
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Post by ericabelle on Oct 23, 2022 7:30:20 GMT -5
So, I took the two pieces in the first photo to a Rock, Gem, and Mineral Show in Springfield, MO yesterday to have it ID'ed. The local club had several people doing this at the show. The man that looked at it said it was limestone, just in layers that were colored by minerals. Iron is responsible for the red band. The white areas he said were where the limestone had dissolved and recrystallized. Let me know if you agree. The way it scratches, it seems a bit harder than limestone (maybe that's the iron?); but the slightly softer tan layer definitely scratches like limestone. So, with what little I know, I could see it being limestone. I could tell the man wished I had brought other rocks from the collection I bought, and I should have. I've got some puzzling green ones. LOL But, anyway, I think it's really pretty. I don't know if I can get a polish from it, but I'll definitely cut it and practice carving it.
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Post by fernwood on Oct 23, 2022 8:02:09 GMT -5
I have some similar that was sold as banded onyx. It was from a landscape place.
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ericabelle
spending too much on rocks
Instagram acct: @erica_shoots_everything
Member since April 2021
Posts: 482
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Post by ericabelle on Oct 23, 2022 9:31:15 GMT -5
I have some similar that was sold as banded onyx. It was from a landscape place. Did yours turn out to be onyx? Mine are definitely softer than onyx
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Post by fernwood on Oct 23, 2022 9:34:08 GMT -5
Mine are about 5 hardness.
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oldschoolrocker
fully equipped rock polisher
Member since January 2019
Posts: 1,578
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Post by oldschoolrocker on Oct 23, 2022 9:38:13 GMT -5
I think fernwood is correct. It looks like mataerial sold to me as Pakistani banded onyx. Softer material so easy and quick to shape cabs and even quicker to polish. fun stuff!
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ericabelle
spending too much on rocks
Instagram acct: @erica_shoots_everything
Member since April 2021
Posts: 482
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Post by ericabelle on Oct 23, 2022 9:43:18 GMT -5
fernwood - well, that seems about the hardness of this stuff; so maybe it's one and the same. oldschoolrocker - interesting! I'll have to play with this. I bet it looks very different polished!
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oldschoolrocker
fully equipped rock polisher
Member since January 2019
Posts: 1,578
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Post by oldschoolrocker on Oct 23, 2022 9:47:56 GMT -5
I have some similar that was sold as banded onyx. It was from a landscape place. Did yours turn out to be onyx? Mine are definitely softer than onyx The onyx I believe is just the trade name for it. It's much softer like 3-5 mohs. I believe it's a type of banded calcite tbh. I've worked quite a bit of calcite before and the Pakistani onyx worked much the same as the calcite.
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ericabelle
spending too much on rocks
Instagram acct: @erica_shoots_everything
Member since April 2021
Posts: 482
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Post by ericabelle on Oct 23, 2022 9:59:52 GMT -5
rockpickerforever , Ah, calcite - that makes sense. It seems a lot of rocks are labeled as onyx that aren't onyx! I guess it makes it sound more valuable than calcite. But, dang, I don't care what a rock is if it's pretty!
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Post by fernwood on Oct 23, 2022 10:12:44 GMT -5
I agree, it's pretty. I am keeping my pieces whole for now.
Mine was part of a salvage operation we were doing at work in the 1990's. SE Wisconsin. There had been a fire at a local greenhouse/landscape business several years prior. The land was being sold. We were allowed to go in and take what we wanted. We salvaged a couple of greenhouses, mulch, potting soil and other things. These landscape rocks were all over the place. I also got a large piece of natural pumice.
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oldschoolrocker
fully equipped rock polisher
Member since January 2019
Posts: 1,578
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Post by oldschoolrocker on Oct 23, 2022 10:23:53 GMT -5
As for getting a polish on it - I've only cabbed the "onyx" but have tumbled a bit of calcite. I have yet to get the level of polish tumbling that I can get on wheels. But have gotten decent polish tumbling calcite w the dry corn cob method. If going to tumble the "onyx" I personally would skip 1st stage grit and start w 120-220 and check it regularly.sjouldnt take more than cpl days tk shape up depending on how rough the pieces are started as. With calcite that I had trimmed up before tumbling it usually didn't take more than a day or two to finish shaping. Then move up stages and polish with dry corn cob media and polish.
If you cab the material there's nothing special I had to do to get high shine polish.
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ericabelle
spending too much on rocks
Instagram acct: @erica_shoots_everything
Member since April 2021
Posts: 482
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Post by ericabelle on Oct 23, 2022 12:35:13 GMT -5
fernwood - wow, that's so interesting that it was used as landscape rock! I would think it would erode rather quickly. oldschoolrocker - thanks for the info! Did you tumble it in a vibe or a rotary? I would like to try to carve it (I have been attempting to carve hearts and practicing on limestone and granite.) I'd really like to polish some of them in my vibe, if that's possible. I don't know if you can do that with limestone, but maybe it can be done with the granite and calcite.
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vance71975
freely admits to licking rocks
Member since September 2022
Posts: 760
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Post by vance71975 on Oct 23, 2022 14:02:53 GMT -5
ericabelle Start with an Old penny (before 1982 if you can) see if that scratches it, If It doesnt see if the rock will scratch glass, If it will, then see if a steel knife will scratch it. The answers will give a basic Idea how hard the rock is. Also Put a few drops of Vinegar on it and see if it bubbles, if it does then it may be a type of Calcite.
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Post by fernwood on Oct 23, 2022 14:24:42 GMT -5
ericabelle You made me curious, so I had to dig out one of my rocks. It is sold as banded onyx or banded travertine. Was a common landscape rock here for many years. I have not seen any for a while. The white, quartz like area appears to be calcite, but it is harder than 3. The red, banded areas are slightly magnetic and about a 6 hardness. The tan bands are softer, say a 5. I did leave some outside over Winter. One of them had the white area split off. Probably due to freezing and thawing. Sorry about the fly. It came inside a couple days ago to warm up.
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ericabelle
spending too much on rocks
Instagram acct: @erica_shoots_everything
Member since April 2021
Posts: 482
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Post by ericabelle on Oct 23, 2022 15:59:22 GMT -5
ericabelle Start with an Old penny (before 1982 if you can) see if that scratches it, If It doesnt see if the rock will scratch glass, If it will, then see if a steel knife will scratch it. The answers will give a basic Idea how hard the rock is. Also Put a few drops of Vinegar on it and see if it bubbles, if it does then it may be a type of Calcite. Thanks, as I stated in my first post, a stainless steel nail will scratch it, but it is difficult. I haven't tried vinegar because I can't stand the smell of it, but I need to clean some rocks with muriatic acid soon, so I'll try with it when I get set up with it.
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ericabelle
spending too much on rocks
Instagram acct: @erica_shoots_everything
Member since April 2021
Posts: 482
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Post by ericabelle on Oct 23, 2022 16:07:24 GMT -5
fernwood That certainly looks like what I have, and it sounds like the individual hardnesses of each layer, too. Mine was not magnetic, but I have some other examples of it with thicker red layers like yours, so they may be. I posted a different batch of rocks several days ago for ID, and it turned out to be banded calcite or rootbeer calcite; but it is also sold under the name "banded onyx" and "travertine". It is too bad some sellers don't just call a rock what it actually is, but maybe this rock is too complicated for one simple name.
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Post by rockpickerforever on Oct 23, 2022 16:19:47 GMT -5
rockpickerforever , Ah, calcite - that makes sense. It seems a lot of rocks are labeled as onyx that aren't onyx! I guess it makes it sound more valuable than calcite. But, dang, I don't care what a rock is if it's pretty! I believe Mel Sabre52 said it is more honestly called Travertine Onyx. It is soft, and would probably make better carving material than cabbing.
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Post by fernwood on Oct 23, 2022 16:29:37 GMT -5
I agree. This material is very complicated. But it is beautiful. I had a good friend who used it for a retaining wall. That did not work out as planned. The Wisconsin Winters caused lots of breakage.
Maybe I will get brave and attack one of mine on the tile saw, trim saw and ry to make some cabs of it in 2023.
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vance71975
freely admits to licking rocks
Member since September 2022
Posts: 760
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Post by vance71975 on Oct 23, 2022 17:54:03 GMT -5
ericabelle Start with an Old penny (before 1982 if you can) see if that scratches it, If It doesnt see if the rock will scratch glass, If it will, then see if a steel knife will scratch it. The answers will give a basic Idea how hard the rock is. Also Put a few drops of Vinegar on it and see if it bubbles, if it does then it may be a type of Calcite. Thanks, as I stated in my first post, a stainless steel nail will scratch it, but it is difficult. I haven't tried vinegar because I can't stand the smell of it, but I need to clean some rocks with muriatic acid soon, so I'll try with it when I get set up with it. ericabelle sorry I missed that part in the first post.
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vance71975
freely admits to licking rocks
Member since September 2022
Posts: 760
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Post by vance71975 on Oct 23, 2022 17:59:52 GMT -5
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