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Search found 688 matches |
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Peter Megaw Replies: 11 Views: 689 |
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Sorry, misread locality...not Nanisivik so forget MVT
These Indian deposits are hosted in basalts...so different source and explanation, but still one of hundreds of calcite environments and fluore ... |
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Peter Megaw Replies: 11 Views: 689 |
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Calcite has a very wide range of fluorescent responses stemming from a wide range of trace amounts of activators and sensitizers. This is a VERY deep rabbit hole you have headed down...
The orange ... |
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Peter Megaw Replies: 9 Views: 703 |
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The little green crystals in your second photo look more right for datolite | |
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Peter Megaw Replies: 9 Views: 703 |
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I wondered that too...UV would tell too and it's nondestructive. Datolite is also harder (5+ vs 3) so a well placed pin will tell you a lot | |
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Peter Megaw Replies: 9 Views: 703 |
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I agree with Kevin's calls on the associated species (I suspect the calcite is orange-pink fluorescent, which unfortunately doesn't narrow things down either). However, neither the habit nor the color ... | |
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Peter Megaw Replies: 2 Views: 548 |
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Hello Nirvash, What you have is clearly a quartz crystal. When quartz is purple it is the variety amethyst. There are a range of colored quartzes, with pretty much every color getting its own name | |
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Peter Megaw Replies: 4 Views: 711 |
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These are oxidized pyrite cubes. They are now some form of hydrated iron oxide... You can call them "goethite pseudomorphs after pyrite". These are called "limonite dice" in the s ... | |
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Peter Megaw Replies: 4 Views: 657 |
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Thanks for posting. There is a guide on the home page to features we like to see to help make identifications, please check it out so you can get an idea how hardness, streak etc. help.
That said, ... |
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Peter Megaw Replies: 8 Views: 1363 |
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Danke Sehr | |
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Peter Megaw Replies: 8 Views: 1363 |
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Schafstiel = sheep stem or sheep stalk = ram's horn? Would fit the shape | |
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Peter Megaw Replies: 2 Views: 659 |
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Hello, We don't want to seem unfriendly, but this forum is for discussion of various non-commercial aspects of minerals and mineral collecting, we expressly do not get involved in valuations or sales. | |
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Peter Megaw Replies: 13 Views: 2313 |
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John Betts gave a great talk on a really simplified SG test at Rochester a few years back, He generated a video of it which is posted on John Betts Fine Minerals website.
Add the www. to the below ... |
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Peter Megaw Replies: 12 Views: 3128 |
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Por mi parte...no es de Mexico | |
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Peter Megaw Replies: 5 Views: 1926 |
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Sir Charles in action at TGMS.
I felt I had arrived as a collector when Charles looked at a recently acquired specimen in my collection and said "that's an important piece!"...and almos ... |
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Peter Megaw Replies: 8 Views: 1789 |
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John...I'm going to go along with Lluis...probably a manganese oxide, given the amount of zinc around likely chalcophanite...it is very common at Santa Eulalia and Ojuela and often has that quasi blui ... | |
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Peter Megaw Replies: 6 Views: 2583 |
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Hello, somehow missed this. I also have paratacamite that looks like this and would agree with Alfredo that an arsenate from Boleo would be exceptional given an overall lack of arsenic | |
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Peter Megaw Replies: 1 Views: 1341 |
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An elderly neighbor recently gave me this interesting hoppered octahedral (?) pseudomorph. He was an industrial minerals geologist who specialized in sulfur, zeolites and evaporites, but doesn't reme ... | |
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Peter Megaw Replies: 4 Views: 2356 |
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https://www.foro-minerales.com/forum/gen_imag/Cristales_Naica-Chemical_Society_Reviews/Cristales_Naica-Chemical_Society_Reviews.pdf
Here is a much more detailed treatment of the science... Still ... |
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Peter Megaw Replies: 2 Views: 2958 |
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Tom, You might try Andy Stucki at Siber and Siber in Zurich | |
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Peter Megaw Replies: 3 Views: 2020 |
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Roger, Ajoite is famous for "deteriorating" into chrysocolla, so my first guess would be that that's what you're seeing rather than a compositional shift within an ajoite-XXX series. (yes, I ... | |
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