nemesis21
noticing nice landscape pebbles
Member since August 2017
Posts: 88
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Post by nemesis21 on Sept 1, 2017 15:12:57 GMT -5
Found some material recently that has a green(some blue) tinting and I was trying to get some ideas of what it might be. I started thinking it might be caused by copper and might be malachite. The malachite I've lookd up seems like a much darker color so I was wondering if this is maybe quartz with some copper staining in it? Fluorite maybe? Also, are these crystal formations on the first one normal or is it likely that it's a fossil of some sort? Fluorite forms square crystals I guess. The 2nd piece has a blue tinted strip a few mm wide which may be a separate material. The white crystals are brittle or glacially broken, but the green material isn't and doesn't scratch. The third picture has a lot going on. It appears to be fossilized algae(jasper/chalcedony), but it also has some greenish tint in some areas. It's probably a different material from the first 2 though. Olivine maybe? All three are from central MN glacial till. Right click images/open in a new tab for full size or go to full imgur album: imgur.com/a/4SANo. #1 #2 #3
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Post by coloradocliff on Sept 1, 2017 15:36:38 GMT -5
You got a few good people from Wisconsin and Michigan who will be by and get you on the material. Doesn't look like any of our Colorado material. The agate looking one sure is nice. Possible laker or a small prairie would be my guess. Fortification pattern, probably a laker. If not think prairie agate. Iron out will clean quartz or fluorite without hurting the crystal. The crystals look pretty glacially ground. Here some fluorite from Idaho in first picture and a Colorado one in second picture. A picture of quartz so you can look at it closely and compare it to your specimen.
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nemesis21
noticing nice landscape pebbles
Member since August 2017
Posts: 88
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Post by nemesis21 on Sept 1, 2017 16:04:12 GMT -5
Yea it's sometimes hard to tell when something might be crystals with glacial activity wearing it down. Most of it is definitely ground down but in the crevices there are some completely flat crystal surfaces. I don't see any fortification banding on last one. It's more like a squiggly line with some random imperfect circles thrown in. I guess it's possible it is a laker with some kind of strange plume/mossy formation. I've never seen anything quite like it though. I'll see if I can get a better picture and clean up the crystals. Update: The first one with the square crystals definitely has some calcite on top that is dissolving away rapidly. I'm pretty sure I can see flecks of copper lodged in it as well. I'll let it soak a bit more and see if it's any clearer. The 2nd one sat for a while and didn't get any clearer/cleaner so who knows.
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Post by coloradocliff on Sept 2, 2017 2:16:38 GMT -5
Looking a lot like a laker.
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Post by fernwood on Sept 2, 2017 4:28:16 GMT -5
That would be a very unique laker for sure.
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Post by coloradocliff on Sept 2, 2017 10:01:40 GMT -5
That would be a very unique laker for sure. HAve a laker that looks a bitlike I imagine that to look like. Just handled it lately and that perked the suggestion. Be interesting to see a cleaner picture later on. No ideas on ID you would care to hazard Miss Fernie?
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Post by wigglinrocks on Sept 2, 2017 10:16:30 GMT -5
First couple look to be quartz types with copper mineral influence , copper sulfates in the recipe when they were formed . Malachite , chrysocolla or others , still copper . #3 could be a mossy laker .
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Post by fernwood on Sept 2, 2017 10:24:27 GMT -5
That would be a very unique laker for sure. HAve a laker that looks a bitlike I imagine that to look like. Just handled it lately and that perked the suggestion. Be interesting to see a cleaner picture later on. No ideas on ID you would care to hazard Miss Fernie? Sure, Cliff, put me on the spot here, lol. I see some oolites. Also some copper or iron colorations. Part of it looks like jasper and part agate. Some quartz inclusions. I am not that great on "official names". In retrospect, I do not think this is a laker. Maybe something from Canada that the glacier dropped off. Very unique for sure. My best description would be a conglomerate oolictic agate type formation with either copper/iron/lead staining. Possible inclusions of one of the many green quartz type rocks in the Upper Midwest. A better photo or several with close ups would help. Ok, I admit, a cop out ID. Just need more photos to understand more. Thanks coloradocliff.
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nemesis21
noticing nice landscape pebbles
Member since August 2017
Posts: 88
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Post by nemesis21 on Sept 2, 2017 16:24:07 GMT -5
I don't have a macro lens/mode on my camera so that's prob the best picture I can get you. Wasn't really concerned with what it was, more what was making the green coloring. If it is a laker it's probably the strangest one I've found. Thanks though!
Also, the first two are definitely something copper related. I can see flecks of copper in the first one for sure, but half of it appears to be calcite crystals(dissolving) and the other half green crystals. They are pretty hard so I doubt they are chryscolla/malachite, maybe some copper stained quartz.
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Post by wigglinrocks on Sept 2, 2017 16:28:15 GMT -5
Could also be Prehnite
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Post by coloradocliff on Sept 2, 2017 16:40:02 GMT -5
Well two of Wisconsin's finest just gave you their look and words. Just send my 5 cent consulting fee in pennies so I can be Rich.. Yep Fernie, sure would like to see that little agate polished cleaner. Also wish I could say prehenite.
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Post by coloradocliff on Sept 2, 2017 16:41:26 GMT -5
BTW Fernie and Rich, Do you guys have any fluorite up in your neck of the Woods?
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nemesis21
noticing nice landscape pebbles
Member since August 2017
Posts: 88
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Post by nemesis21 on Sept 2, 2017 17:27:02 GMT -5
A book I have says there is fluorite in the far northeastern tip of MN along Lake Superior(north of Grand Marais). It's probably scattered around from glacial activity in the area, just like all the other rocks I find. I'd venture a guess to say it's probably not that common though.
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Post by wigglinrocks on Sept 2, 2017 17:57:24 GMT -5
BTW Fernie and Rich, Do you guys have any fluorite up in your neck of the Woods? I'm totally clueless , but you knew that already .
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Post by coloradocliff on Sept 2, 2017 18:35:44 GMT -5
BTW Fernie and Rich, Do you guys have any fluorite up in your neck of the Woods? I'm totally clueless , but you knew that already . Well I heard you were but x wives can be so cruel at times.
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Post by fernwood on Sept 3, 2017 4:26:02 GMT -5
BTW Fernie and Rich, Do you guys have any fluorite up in your neck of the Woods? I'm totally clueless , but you knew that already .
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Post by fernwood on Sept 3, 2017 4:26:37 GMT -5
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