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Post by rockpickerforever on Oct 9, 2018 17:59:57 GMT -5
Picked this rock up at the swapmeet a couple weeks ago for a buck.
Probably not any one name you can put to it, as I think it has several components. The largest identifiable percentage is the purple, which I am sure is amethyst. But maybe not? Also has some clearish quartz, and some black mica.
Maybe the yellowish is citrine? Anybody have any thoughts?
Thank you in advance. Jean
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Deleted
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Post by Deleted on Oct 9, 2018 21:51:41 GMT -5
I've seen mica and lepidolite chunks that looked like that. Any harder black crystals could be schorl tourmaline (some of the purple and/or yellow could also be tourmaline). I'm just not seeing any crystal terminations or enough faces to say for sure. Amethyst/quartz/citrine might also be possible, though. You might try extracting a crystal or two from the mica to see if there might be more structure to ID.
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Post by rockpickerforever on Oct 9, 2018 23:09:26 GMT -5
Thanks, @rocks2dust, will give that a try. Will try to liberate a purple chunk to better assess it.
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NRG
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Post by NRG on Oct 11, 2018 17:59:55 GMT -5
In no way to I mean to impune the previous reply. I mean to offer more possibilities. That purple looks like garnet to me. Is it true on your screen? The color I mean. gemfeller
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NRG
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Post by NRG on Oct 11, 2018 18:23:26 GMT -5
1daveCan citrine and garnet be in the same stone? Chemically I mean.
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Post by rockpickerforever on Oct 11, 2018 19:44:55 GMT -5
1dave Can citrine and garnet be in the same stone? Chemically I mean. I've been told amethyst and citrine are chemically the same. When mixed together, they are called ametrine.
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Post by rockpickerforever on Oct 11, 2018 19:46:29 GMT -5
In no way to I mean to impune the previous reply. I mean to offer more possibilities. That purple looks like garnet to me. Is it true on your screen? The color I mean. gemfeller The colors are true. The purple part is the color of a grape popsicle. Purple, not the burgundy of a garnet.
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gemfeller
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Post by gemfeller on Oct 11, 2018 20:17:56 GMT -5
In no way to I mean to impune the previous reply. I mean to offer more possibilities. That purple looks like garnet to me. Is it true on your screen? The color I mean. gemfellerThere certainly are almandine garnets of that color. But I agree with R2D that there's insufficient crystal structure showing to venture a reasonable guess. I'm not able to say whether garnet and citrine can exist together. Citrine is usually heated amethyst (naturally but most often not; in fact natural citrine is fairly rare.)
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gemfeller
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Post by gemfeller on Oct 11, 2018 20:42:08 GMT -5
1dave Can citrine and garnet be in the same stone? Chemically I mean. I've been told amethyst and citrine are chemically the same. When mixed together, they are called ametrine. Natural Ametrine is pretty rare stuff. Apart from the classic Anahi location in Bolivia, I know of only one or two other occurrences (one is in East Central California). There's a ton of hydrothermal man-made Ametrine on the gem market however. Here's a gemology article that tells the story very well: www.gemologyproject.com/wiki/index.php?title=AmetrineETA: Just for fun, here's a natural Ametrine in a Barion style that I cut sometime back.
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Post by 1dave on Oct 11, 2018 21:10:11 GMT -5
1daveCan citrine and garnet be in the same stone? Chemically I mean. Late to the party and all has been answered. All things are possible, but I would say that would be improbable in the metamorphic heat/pressure scale. Heat amethyst above 450 o and the iron will change valence, turning the color from purple to yellow. The trick is to keep all from making the transition. There must have been some metamorphism or black mica (biotite - a solid-solution series between the iron - end member annite, and the magnesium - end member phlogopite) would not be present. To see the amethyst and citrine intermingled in such a fashion is very interesting. Perhaps a hot fluid stream snaked through a previously all amethyst crystal group?
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victor1941
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Post by victor1941 on Oct 11, 2018 21:47:52 GMT -5
No matter what it is the cab should be spectacular.
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NRG
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Post by NRG on Oct 12, 2018 0:39:10 GMT -5
1daveCan citrine and garnet be in the same stone? Chemically I mean. Late to the party and all has been answered. All things are possible, but I would say that would be improbable in the metamorphic heat/pressure scale. Heat amethyst above 450 o and the iron will change valence, turning the color from purple to yellow. The trick is to keep all from making the transition. There must have been some metamorphism or black mica (biotite - a solid-solution series between the iron - end member annite, and the magnesium - end member phlogopite) would not be present. To see the amethyst and citrine intermingled in such a fashion is very interesting. Perhaps a hot fluid stream snaked through a previously all amethyst crystal group? What I see in that stone is garnet and yellow gold something. I don't see amethyst as the color seems too red for that. This is more of a raspberry. Almandine. I have bolivian ametrine in my collection. It looks nothing like this. gemfeller
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Post by 1dave on Oct 12, 2018 6:46:04 GMT -5
Late to the party and all has been answered. All things are possible, but I would say that would be improbable in the metamorphic heat/pressure scale. Heat amethyst above 450 o and the iron will change valence, turning the color from purple to yellow. The trick is to keep all from making the transition. There must have been some metamorphism or black mica (biotite - a solid-solution series between the iron - end member annite, and the magnesium - end member phlogopite) would not be present. To see the amethyst and citrine intermingled in such a fashion is very interesting. Perhaps a hot fluid stream snaked through a previously all amethyst crystal group? What I see in that stone is garnet and yellow gold something. I don't see amethyst as the color seems too red for that. This is more of a raspberry. Almandine. I have bolivian ametrine in my collection. It looks nothing like this. gemfellerYou may be right. I don't see any concoidal fractures.
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Post by pauls on Oct 12, 2018 15:12:48 GMT -5
Could a specific gravity test help? I know its a mixed rock but if that purple stuff is Garnet and there's a lot of it the specimen itself would be relatively heavy. The third photo with the ball shaped purple bit sticking up does look a lot like Garnet and the specimen itself looks a lot like the sort of rock you'd expect to see garnet.
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Post by drocknut on Oct 12, 2018 15:21:14 GMT -5
I'm thinking it's more of a massive amethyst mixed rock with iron stained quartz. Not sure it is citrine but anything's possible. Here's a cut of a chunk of massive amethyst I found here in Arizona. Notice it has weird patterns like the amethyst is squished with the other quartz.
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Post by fernwood on Oct 13, 2018 5:04:01 GMT -5
Here is part of a large piece I found near Thunder Bay at an Amethyst mine. Has some similar colors to yours. Much of what we found was iron stained and it gave a reddish hue to the crystals. colors
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Post by 1dave on Oct 13, 2018 9:37:22 GMT -5
Above obviously quartz striations. Below more like garnet shapes.
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Post by rockpickerforever on Oct 13, 2018 10:05:19 GMT -5
Above obviously quartz striations. Below more like garnet shapes. Or blueberries! Stiil need to dig a berry out to get a better look at it. fernwood , no idea on your stone. It does look like quartz, but isn't that what amethyst basically is? Quartz with coloring ingredients. So many variables, God's recipe.
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Post by rockjunquie on Oct 13, 2018 10:49:09 GMT -5
I have resisted posted my 2 cents. To me it looks like ruby in something. Maybe it's ruby SPINEL in schist? With less black than is usual- maybe from the outer edge of the rock. But that pink color (on my monitor) looks like ruby or ruby spinel.
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Post by rockpickerforever on Oct 13, 2018 11:50:17 GMT -5
Thanks for your 2 cents, rockjunquie . It's funny, the photos I posted are a perfect color match, in both my camera and on my computer monitor (and cell phone) to the rock in hand. It really is grape popsicle purple, lol.
I think the differing perspectives people are seeing are due to differing monitors on their end.
Weather cold (65° lol) here and we will probably be getting more rain today. Had a bit of thunder and lightning around 8:30 last night. We only had a little bit of rain overnight, but Ocotillo Wells had over 1 1/2 inches! I can just hear all the desert plants sucking up the water (first real rain in I don't know how long, many months at the least) and going, "Ahhhhhhh!" Also thinking of the delicious smell of a wet desert. Was going to say envisioning it, but that's not quite right when talking about a smell. Well, I'm sure you get what I am talking about.
I want to go out and dissect this rock, but DH is sick in bed sleeping , so don't want to be making a lot of noise right now. Maybe I can do it quietly, without use of power tools? Will do what I can. I know you guys are all dying to see what it is, so am I!
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