Lapidaryforum.net
Let's Rock => Identifications of Materials => Topic started by: Slabbercabber on April 24, 2018, 03:36:41 PM
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This is from an estate sale. The specimens were all labeled with numbers but there was no corresponding key. The hardness is around 4 or 5 with no discernable streak. Red stars on a black matrix would seem to be unique but I don't recall having seen it before.
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Any chance it could be cinnabar?
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Exactly what I thought. You do not want to cut cinnabar.
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ooh the nasty mercury rock.
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Too hard for cinnabar and it has no streak. Cinnabar leaves a very distinct red streak. I'm thinking it looks like nodules I have found at Yellow Cat, but I can't remember what they were. Oldtimers is catching up with me.
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I think you're right, Slabbercabber. Some of our club members go to Yellowcat every year, and we have some here that look like that. I also can't remember exactly what they are right now.
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I'm thinking it looks like nodules I have found at Yellow Cat, but I can't remember what they were.
I think what you may be remembering are the chalcedony after barite pseudomorph nodules from Yellow Cat. I think I still have one or two somewhere around here, though not in the pretty red of yours. The barite original crystals accounted for the crisscross inclusions, and sometimes more obvious when you saw them in half.
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I was going to post the Yellow Cat nodules when I first read the post but I was having trouble identifying them but I think you are right with the Chalcedony after Barite. I have a little box full of them and although they are interesting not much you can do with them. I pulled 2 out today to show a pic. After looking at them I am leaning more towards Cinnabar.
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I have a little box full of them and although they are interesting not much you can do with them. I pulled 2 out today to show a pic. After looking at them I am leaning more towards Cinnabar.
Those look like great barite specimens, and the Yellow Cat area has those, too. The pseudomorph nodules usually look different, however, with the top of the thin crystal blades generally knocked off. While barite is too soft to cab, the pseudomorphs have had the barite replaced and are pretty solid and can make good cab material. The more solid barite pseudomorphs from Yellow Cats and McDermitt areas often gets confused with sagenite agate once sliced. I wish I knew where I put my examples, but there are some photos of this material on the 'net (e.g., the old auction here (https://www.worthpoint.com/worthopedia/mw-red-agate-after-barite-pseudomorph-1671221838) and this collecting trip (http://www.peaktopeak.com/njeffco/2007/yellowcat/yc07_2.php)). They come in several color combos, and I don't think that the red comes from cinnabar (especially as it is too hard for cinnabar and doesn't streak red).
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Yes, barite is what I was thinking of. White streak would not show up on my white ceramic. Thank you.