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Post by Peruano on Jun 26, 2022 7:35:59 GMT -5
I was asked to slab a rock an artist had bought on the internet. It was one of those rocks that had been polished and to my eye strikingly beautiful such that many would not have wanted to slice it and "ruin" it. But then you never know whats inside. Many rocks are prettier inside than out, but. . . this one was definitely a dye job. The two slabs on the outside are interior face cuts, the two in the middle are the external surfaces that were visible when purchased. 20220521_091331 by Thomas Fritts, on Flickr Here are two more views of interior faces just to show that things got less brilliant as we went further in. 20220521_091307 by Thomas Fritts, on Flickr You can't judge a book by its cover. I'm glad I didn't pay big money for the stone.
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herb
spending too much on rocks
Member since November 2011
Posts: 444
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Post by herb on Jun 26, 2022 7:57:30 GMT -5
Interesting! That looks like a Mad River agate from Madagascar. Out of curiosity, I search on google images for Mad River agate and a quick glance shows about half the images with the browns of the outside of your rock and the other half are much more white. I always assumed brown was the natural color of them, but apparently not!
At least it is a better dye color than those gaudy blue and purple Brazilian agate slices you see everywhere
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Post by Peruano on Jun 26, 2022 15:35:53 GMT -5
I agree. Its hard to believe someone thinks those garish colors of dyed agates are improvements, but they do sell them to someone, sometimes.
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rewdownunder
spending too much on rocks
Member since March 2012
Posts: 357
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Post by rewdownunder on Jun 26, 2022 19:31:16 GMT -5
Are they dyed or were they heat treated? I remember reading they are heat treated to bring out the color.
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Post by jasoninsd on Jun 26, 2022 19:38:39 GMT -5
I've been curious about those...thanks for posting the information and pics!
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Post by Mel on Jul 1, 2022 15:29:31 GMT -5
Even though these are dyed, they are quite pretty. Just not as pretty as they would be if natural... And Peruano, those dyed agates drive me mad. I've had people ask me where to find such amazing stones and it's a bummer watching their faces when I to tell them that hot pink agates are made in a lab.
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Post by rmf on Jul 2, 2022 2:39:40 GMT -5
You might try to dye the outer pieces. step 1 soak in Tri-sodium phosphate to remove all oil step 2 soak in ferrous sulfate solution step 3 dry and place in stainless container filled with sand, bury rocks in sand, heat slowly until rocks are over 212 deg F so they don't fracture back at 450-500 deg F over night and let cool for 24hrs without removing from oven.
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Post by Peruano on Jul 2, 2022 6:30:59 GMT -5
I'm not trying to be overly picky, but . . you say dye when you are really describing heat treatment. The TSP is a degreaser. I'm under the impression that this stone was treated with a chemical and not just heat, but maybe I'm wrong. I did note Rewdownunder's suggestion.
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Post by rmf on Jul 4, 2022 0:44:57 GMT -5
I'm not trying to be overly picky, but . . you say dye when you are really describing heat treatment. The TSP is a degreaser. I'm under the impression that this stone was treated with a chemical and not just heat, but maybe I'm wrong. I did note Rewdownunder's suggestion. No Dye is the correct term. TSP is a degreaser as you say that is to remove all saw oil to improve penetration. It is the Ferreous Sulphate that is the dye. If the stone will take it up then it will get a brownish color and once it is absorbed then the heat changes the state of the iron atoms to a hematite which is read. So dye with heat treat. But it is a natural dye. I pulled ferreous sulphate from old coal mine works where the pyrite had decomposed to ferreous sulphate. At that point I did not know what it was.
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