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Post by snowmom on Mar 21, 2015 12:18:22 GMT -5
Got to go out to one of my favorite beaches yesterday and picked this up along with a few other interesting rocks. This is a public beach and it was full of foot tracks where others had picked before me. There were people there when I got there and more arrived as I was leaving. competition is tough and many beaches are too ice covered still to go hunting. Now i'll be checking out all the other beaches to see what I can find. Mad rock hunting rush is on to see what the ice heaved onto the beach and left behind. (fun to do)
This rock is 4x 3.5x 1.6 inches at its widest points, weighs over 500 grams (as high as my little scale will weigh, buried the needle) It is translucent in the pink areas and opaque in the darkest areas. Seems to have a few flecks of oxidized copper throughout I just learned about patricianite on a facebook group. Didn't know it was prehnite. The only prehnite I was familiar with was the pastel apple green kind. This piece seems to be stained yellow from all the iron in the water. I would like to soak it in some muriatic acid solution but am very worried about doing damage to it. Anybody know what muriatic acid will do to prehnite? I may try a tiny drop somewhere on it and see if it implodes or something! comments and suggestions most welcome! thanks for looking.
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Post by washingtonrocks on Mar 21, 2015 12:28:40 GMT -5
Beautiful! Love its luster!
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Post by gingerkid on Mar 21, 2015 13:08:28 GMT -5
snowmom, I checked mindat to see if I could find any photos of patricianite, but they did not have any posted. Google images mainly revealed pictures of what "looks" like thompsonite, but is pink in color with pinkish orbs. Not sure what will happen if you pour muriatic acid on it. Found a blog entry from the Agate Lady that you may want to read: agatelady.blogspot.com/2013/09/difference-between-prehnite-and.htmlAt the bottom of the Agate Lady's blog, I found this from the link she provided: "Many specimens and gemstones with well defined "eyes" and originally thought to be thomsonite have been shown to be prehnite that appears pink because of internal reflections from very fine, evenly disseminated grains of native copper. I once examined almost 100 specimens labeled "thomsonite" from the Keweenaw Peninsula of Michigan's Upper Peninsula -- kindly supplied by members of the Michigan Mineralogical Society -- and found more than 50 percent (in fact, nearly 60 percent) of them to be prehnite. See also Huber (1983)." Source: stoneplus.cst.cmich.edu/thomsonite.htm
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Post by snowmom on Mar 21, 2015 13:28:16 GMT -5
Thanks Jan, there is precious little out there. In the over 2 thousand mindat photos of prehnite, there are about 6 or 7 that show patricianite (I looked at them all and THEN I noticed I could search for Michigan prehnite gak!)I saw some from Italy that also looked similar, the only 2 places that had stuff which looks like this. It has to do with the copper inclusions in it causing the different colors. I have already been to the pages you posted links for. There really is very little in google land about it. I put pictures up on the facebook UP rocks and minerals page so maybe one of the 3 members who make jewelry out of it can identify it for sure. I found one site which has slabs of prehnite/as patricianite for sale, and have seen some photos of stuff that looks suspiciously like the stuff I posted here over Christmas. I think I can see the similarities between those... feeling like a 'slow' pupil as I try to sort it all out. here I love a good mystery, but only if somebody can solve the puzzle at the end. I'll keep plugging along and one day the light will dawn.
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Post by snowmom on Mar 21, 2015 13:49:26 GMT -5
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Post by washingtonrocks on Mar 22, 2015 12:53:05 GMT -5
snowmom, have you ever run across any Datolite in your travels? I knew someone who used to sell some pink Datolite from MI that resembled your rock quite a bit. That stuff was pricey!
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Post by snowmom on Mar 22, 2015 14:04:47 GMT -5
Most of that stuff comes from around the UP and is too fragile to have made it across the lake with the glaciers- I know it is rare, usually smaller than palm sized, and expensive. Sought after for jewelry. - I don't have any datolite, but Jugglerguy might, since he collects from the UP. I did hear from a member of my other boards, he doesn't think it is patricianite, I don't know if the other 2 will chime in or not. No offers of alternative ID were made. Meantime have found that hydrochloric acid should make it fizz if it is patricianite. I will try a drop and see. If it doesn't, then it is some sort of silica(quartz/agate/etc) or feldspar... The green matrix could be almost anything. I do see flecks of green which I think are oxidized copper... maybe that will turn out to be nickel. So confusing! (shakes head)
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Post by mohs on Mar 22, 2015 14:40:35 GMT -5
I'd be real interested to see that rock slice opened I get fooled by something similar that I always pick up. What looks like agate- after cutting its usually a whitesh opaque material-- like a marble? anyway I just found one those type of rocks and threw it a cairn I'm gathering around the workplace. I'll recover it and post sometime later....
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Deleted
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Post by Deleted on Mar 22, 2015 16:15:07 GMT -5
Just learned about it? Found it on next trip? Luck? Or confirmation bias?Chip it with a hammer to see inside color, then decide which of the above is true.
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Post by snowmom on Mar 22, 2015 17:10:03 GMT -5
Master Shotgunner : After learning about the stuff and seeing the meager photos available I was anxious to go out specifically to try to locate some of it, you bet! How else does one learn when self taught? There are so few reference photos available and I have so little experience, I could not learn if I did not attempt to put into practice the clues I garner from the internet. It is one thing to read about something, another to understand and translate that information into successful hunting. I hesitate to whack it with a hammer, if it does turn out to be patricianite it could do a great deal of damage. If it isn't patricianite it is still a pretty neat rock. Prenhite is 6 to 6.5 Mohs, Feldspar or Quartz the same or much higher. I'd have to whack it awful hard to break it. ( won't do that yet) If it is a rock form that is familiar to you, I would like to hear about it. Thank you!
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Post by Jugglerguy on Mar 22, 2015 18:26:33 GMT -5
In the box of rocks that I dropped off at your house, there's a small pink rock that I think might be prehnite that I picked up in the Keewenaw peninsula. It looks like this: Untitled Here are some other rocks that may be prehnite: UntitledThis one I'm pretty sure is prehnite because it has an eye. Untitled
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Post by snowmom on Mar 23, 2015 6:57:29 GMT -5
I did see the one in the box of rocks which is here and thought that it had to be prehnite patricianite. Jugglerguy. The others you posted look a lot like that one. In my case it is hard to know what I am looking for if I have never seen it. Like looking for somebody in a crowd when you have only seen photos of their family. (and I'm not good with faces) Thanks for the pictures. I need to get that box of delicious polished rocks back to you soon.
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Post by snowmom on Mar 23, 2015 7:10:12 GMT -5
So late last night I had a little session with the rock above. At Shotgunner's suggestion, I hit it with a 4 lb sledge. Finally stood it on one edge and managed to whack it just right, turned the stuff to powder. When the powder was swept away there was a fracture which made me think of feldspar. Looking closer I found deep texture in the pink rock that looked like sunstone. In a few other places there are hints of feldspar cleavage, but most of the pink looks to be non crystal in makeup. There is white material surrounding the deep pink. There are metal inclusions which I worked at with a tiny grinder point. removing the green granular powdery looking oxidation revealed grey/lightly metallic looking long sharp or sharply triangular shards. The powdered rock was placed in a dish and a drop of muriatic acid added. It did not fizz, so no calcium. Slept on all of this and I think it is a pegmatite where the granite components separated and formed as large bits of feldspar(pink) surrounded by white and covered thickly over most of the rock with clear (quartz) and the dark (olivine/or some other green material) migrated only slightly. The metal shards and dust were left as spice throughout the rock probably by whatever precipitated the rock's meltdown in the first place. I suppose I could call it some sort of unakite since it is pink, green, and white... but that might be cheating. Set me straight and teach me something if I have this all wrong! I am here to learn. thank you
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Post by snowmom on Mar 23, 2015 7:22:07 GMT -5
showing metal shards inclusions showing the area smashed by sledge and resulting breakage pattern. this rock is about 6-6.5 Mohs, does not attract a magnet.
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rockroller
spending too much on rocks
Be excellent to each other.
Member since October 2013
Posts: 359
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Post by rockroller on Mar 23, 2015 11:50:53 GMT -5
snowmom, Did you draw this face on the rock before you smashed it with the hammer?!? Who's it supposed to be? =) ~Roland
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Post by drocknut on Mar 23, 2015 12:05:39 GMT -5
Loli saw the face too.
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Post by Jugglerguy on Mar 23, 2015 14:17:40 GMT -5
When I first read this, I thought Snowmom hit my little tumble with a sledge hammer. Thanks for not hitting my rock. No hurry getting those back to me unless you start swinging that hammer around them.
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Post by snowmom on Mar 23, 2015 17:48:53 GMT -5
LOL Roland, I saw that face when I posted it, wondered if anybody would comment. RTH people are faithful! You didn't let me down!
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Post by snowmom on Mar 23, 2015 17:51:21 GMT -5
Diane, I need to drink way more coffee before I post things. Yikes jugglerguy Rob, no way would I ever harm that lil beauty! Your tumbles are safe on my kitchen counter, and will remain so (safe!) until returned to you.
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Post by Deleted on Mar 23, 2015 23:22:08 GMT -5
Nothing is learned if confirmation bias causes you to mis-identify granite/pegmatite as some obscure mineral. True learning happens when knowledge is un-affected by any bias.
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