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Post by stoner on May 22, 2007 0:49:08 GMT -5
I've been asked what I think may be going on with a stone that is supposed to be imperial jasper. This person bought this stone from ebay which was described as imperial jasper. She made the necklace and said that while she was washing it off with soap and water, the stone started to look as though it was stained, and as it dried, the discoloration went away in a matter of minutes. Here's a few pics. The first one is before she washed it. You can see a little of the discoloration in this pic. She says the stone has a high gloss finish on it and it feels like stone, but she's wondering if it isn't maybe some type of clay with a glaze on it. In my opinion, it doesn't look like typical imperial jasper and I know that stuff is a porcelean jasper and is very hard, so I doubt it would be affected by soap and water. Any ideas?
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adrian65
Cave Dweller
Arch to golden memories and to great friends.
Member since February 2007
Posts: 10,786
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Post by adrian65 on May 22, 2007 3:20:32 GMT -5
I think the face in the seccond pic is not the same as in the first. The brown little spot is only in the second picture. Also the curved part of the cab seems to be in the second plan in the first pic and towards us in the second pic. Could that lady trick you? Anyway if that pattern disappeared during washing, the stone is in my opinion a fake.
Adrian
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free4rms
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Member since January 2007
Posts: 839
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Post by free4rms on May 22, 2007 5:59:47 GMT -5
I agree with Adrian, I think the two pictures are not both the same side. As far as imperial jasper.... I have one pendant in particular that I made from Imperial that changed quite dramatically in appearance after I had finished working on it on the diamond wheels. Some stones will change color when they are thoroughly wet, and Imperial Jasper can do this. It can sometimes take an hour or more of drying for it to finish changing to the final color. Imperial jasper can also have some softer areas mixed in with the typically hard jasper as some of you who have worked with it might be aware, and it is this softer area that can absorb water and change color. The softer part of the material can be a very pale green/yellowish color, and although it is hard to tell from the photo if this is what the lighter color is, it could be. If the lighter color is the softer material, I think it is a possibility that it could change color quickly when it is wet with soap and water and then change rapidly when it dried. I have to agree that the pendant is not typical, but with the colors in the center spot, there is a chance that it is imperial jasper.
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Post by larrywyland3 on May 22, 2007 6:17:22 GMT -5
I have never seen imperial with all that creamy white stuff. I have only worked up about 5 cabs and bought slabs from one source. All the photos I have seen were different shades of green and some grayish blue, black, but nothing as light as the photo. It almost looks like a cohog shell. They polish really nice and are almost as hard as a jasper. There is no blue green in cohog shells; basically I have no idea what it looks like; its nice looking
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Post by rockyraccoon on May 22, 2007 6:17:26 GMT -5
stoner the look could definitely be simulated with clay but i would think the pendant would feel lighter than stone. i also don't know why the clay would discolor in water. i wonder if holes, pits, etc. were filled with something else that is discoloring when wet. but i have no idea what. does plaster of paris discolor when wet? spackling?
kim
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Post by rockyraccoon on May 22, 2007 6:23:51 GMT -5
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Post by deb193 on May 22, 2007 6:43:00 GMT -5
The royal imperial nodules all have a white/orangeish exterior. This is more chalky than the center. Like some pic jasper with chalky skin, there is a point where the white part is hard enough to shape and polish. It might still be a little more poreous than the colored center.
I have seen pink or green with white adjacent - especially on endcuts. I think it is real, but a bit too much of the softer matrix may have been left.
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Sabre52
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Member since August 2005
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Post by Sabre52 on May 22, 2007 10:10:35 GMT -5
Ed: Daniel is dead on. The Royal Imperial Jasper comes in nodules that are often quite chalky and porous on the exterior. Some exteriors are so chalky as to be easily scratched by a knife and almost like actual chalk. Reminds me of the chalk surrounding English flint nodules. When I cab them, I always have to grind down to the point where the highly silicified porcelain jasper begins. Some interiors are actually highly translucent which I suppose, would make them closer to agate. Color changes can be dramatic but it's a natural material as I've seen the uncut nodules. Probably the cab in question contains some of the more chalky exterior material...mel
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