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Search found 563 matches |
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Pete Richards Replies: 1 Views: 247 |
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Here is a label of a TN specimen I obtained in 1993. It has a distinctive type font, and several of us northeast Ohio collectors have or have had specimens with labels like it. We've been trying to ... | |
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Pete Richards Replies: 6 Views: 446 |
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It is difficult to impossible to decipher crystallography from a photograph, except in the most general terms. The slight re-entrant shown does suggest twinning, but the faces involved appear to be c ... | |
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Pete Richards Replies: 9 Views: 1021 |
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The Unreadable Label
This Unreadable Label has provided quite an entertaining challenge to me and to others. I was interested because it is clearly about crystal faces, although it uses an old (Na ... |
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Pete Richards Replies: 1374 Views: 1304183 |
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Dany can take the last one. I'll take the first one.
Beautiful specimens; masterful photography! Thank you, Ploum! |
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Pete Richards Replies: 9 Views: 1021 |
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If the drawing attached to the label is of this specimen, it appears to be showing a different view. Does the little "wart" on the bottom of the drawing correspond to the slight bump visibl ... | |
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Pete Richards Replies: 10 Views: 795 |
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I agree that it's not a natural stone, but I wonder if the colorless beads are present all the way through the piece, not just on the surface. The light weight suggests to me that it may be some sor ... | |
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Pete Richards Replies: 8 Views: 913 |
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Thanks, Tobi and Andreas Gerstenberg. I could not read that handwriting!
With the help of the translator DeepL, I suggest that a better translation for "Schafstiel" would be "sheep ... |
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Pete Richards Replies: 7 Views: 928 |
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Thanks for the close-up pictures. I think they confirm that the quartz is not continuous throughout, which probably means that the quartz grew as several to many crystals oriented mostly the same dir ... | |
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Pete Richards Replies: 7 Views: 928 |
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Josele, your specimen of quartz on elbaite is certainly interesting. The parallel arrangement of many quartz crystals on the etched elbaite definitely suggests epitaxy.
Is it possible to get some ... |
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Pete Richards Replies: 7 Views: 982 |
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Ken, you have been rightly complimented for trying to do what you can to identify your specimens. But I'm afraid some confusion has crept in. Here are some questions and comments to try to clarify s ... | |
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Pete Richards Replies: 13 Views: 1371 |
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Amir, you probably know all of this better than I do....
I know of no publications. But I wonder - do the spheroids penetrate into the amethyst or are they strictly on the surface of the amet ... |
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Pete Richards Replies: 28 Views: 2860 |
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I have to voice my doubts about the identification of this specimen as chalcopyrite. Sante, you did an incomplete experiment! Smart to test your needle against a known chalcopyrite, but you did not ... | |
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Pete Richards Replies: 5 Views: 746 |
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I agree with Bob - it's gypsum..
If you have one to sacrifice, I'd try to split it down the middle parallel to the biggest flat surface - the surface we see in the first image. It should split a ... |
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Pete Richards Replies: 28 Views: 2860 |
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I forgot to comment that carrolite cannot have a pyritohedron. Its crystal class is 4/m -3 2/m, and in that symmetry class the form in that position would be a tetrahexahedron, not a pyritohedron. | |
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Pete Richards Replies: 28 Views: 2860 |
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Hi, Sante!
You ask excellent questions. Some do not have answers that are at once short and complete! And my reply is neither short nor complete. The semantic questions first: I agree that ... |
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Pete Richards Replies: 28 Views: 2860 |
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John is right to compare the crystal's appearance with a pyritohedron - which also has 12 faces. The similarity can be seen if you mentally rotate my right drawing 90°, in which case the striations i ... | |
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Pete Richards Replies: 28 Views: 2860 |
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This is a very interesting crystal. Pyrite certainly can have rhombic dodecahedron faces, but this is uncommon and such faces are usually subordinate to other, larger faces. With the usual disclaim ... | |
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Pete Richards Replies: 14 Views: 1499 |
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Another good candidate would be feldspar. | |
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Pete Richards Replies: 14 Views: 1499 |
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Perhaps I am geograhically myopic, but where is Bilula? Where is Rodope? | |
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Pete Richards Replies: 4 Views: 1290 |
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There's a tremendous difference between the colors in the photos and the colors in the specimens shown with the spectrum! The colors in the photos are so strongly blue and yellow as to look unreal. ... | |
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