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Fake pyrite concretion?

Posted by Reiner Mielke  
Re: Fake pyrite concretion?
December 12, 2010 06:35PM
    
Rock,

Don't give them any ideas!
avatar Re: Fake pyrite concretion?
December 12, 2010 06:37PM
    
"If they were hammered down from larger blocks of interbeded material I suspect the urge to make other
shapes than balls and egg shapes would cause a variety of other shapes to show up on the market."

Great point Rock, If they were making them where are the hearts and stars.
Re: Fake pyrite concretion?
December 12, 2010 06:37PM
    
Back to my original thought. Assuming they are natural how would something like that form?
Re: Fake pyrite concretion?
December 12, 2010 06:52PM
    
There is in fact a picture of these concretions in matrix (photo 185225) in Mindat!
avatar Re: Fake pyrite concretion?
December 12, 2010 06:54PM
    
Probably in similar fasion to the azurite and malachite concretions from La Sal area of Utah.
Just a different soup.


Pyrite link... [www.mindat.org]

Azurite link...[www.mindat.org]



Edited 2 time(s). Last edit at 12/12/2010 06:58PM by Adam Kelly.
Re: Fake pyrite concretion?
December 12, 2010 07:01PM
Here are some pictures of several more that I own of various sizes:
[www.messingminerals.com]
[www.messingminerals.com]
[www.messingminerals.com]
[www.messingminerals.com]
[www.messingminerals.com]

and something similar from New York State:
[www.messingminerals.com]

I was curious if they were real myself but was reassured by 3 separate well known dealers that they were. Of course that doesn't prove anything. In any case my wife really liked them and said she doesn't care if they are real or not. She has them displayed on our coffee table in a pretty "sculptural" arrangement that we enjoy.

I would certainly like to know how they are formed, either naturally or not, as everyone who sees them asks.
Re: Fake pyrite concretion?
December 12, 2010 07:49PM
    
Thanks for the links to the matrix specimens. I think I now know how they formed. They once were normal concretions with disseminated pyrite in which metamorphism has remobilized the pyrite into bands parallel to the foliation of the rock. However from the looks of the matrix specimen there has been some enhancement by grinding. Also I would say that the concretions with the pyrite sticking out have been enhanced to get the pyrite to stick out ( matrix removed by whatever means). My conclusion is that they are enhanced natural concretions. Thank you everyone for your input!



Edited 1 time(s). Last edit at 12/12/2010 07:51PM by Reiner Mielke.
Re: Fake pyrite concretion?
December 12, 2010 07:58PM
    
I disagree, they are dug out of matrix and soft matrix is removed to show the xls., however, that does not make them enhanced. If that were the case just about any specimen would be considered enhanced!
Re: Fake pyrite concretion?
December 12, 2010 08:24PM
    
Enhanced depends on what the term is relative to. If it were just a pyrite specimen then you are right it is not enhanced with respect to the pyrite, however relative to the concretion it is enhanced since it makes the concretion more interesting in a way that is not natural.
Re: Fake pyrite concretion?
December 12, 2010 08:56PM
Pyrite concretions occur in the black shale above the Great Limestone in Weardale (and other places). I've seen many partially formed/distorted ones with rings of pyrite crystals round them though never such a perfect example as the one shown here. As for abundance, it was easily possible to collect 500 of them in an hour....a lot easier than trying to make them!
Re: Fake pyrite concretion?
December 12, 2010 09:21PM
    
But Reiner the concretion is solid pyrite!
Re: Fake pyrite concretion?
December 12, 2010 10:15PM
    
OK for solid pyrite concretions with no matrix they are all natural (assuming no grinding has taken place to enhance the overall shape), for ones with matrix where some of the matrix has been removed to enhance the pyrite layers thus alter the appearance of a natural concretion they are enhanced. 8-)
avatar Re: Fake pyrite concretion?
December 13, 2010 02:14AM
    
just my two cents. arent many goods imported from china because of the cheap production cost? thats why sprawlmart is filled with ¨junk¨ like that. you dont move jobs and production overseas if the cost is higher. as Reiner has said im sure they could afford it and to crank out a bunch of pieces would soon cover startup costs.

onto how they are formed its interesting but i also believe there is enhancement as you can see in the matrix phot they dont look very appealing to me.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
A buena hambre no hay pan duro
avatar Re: Fake pyrite concretion?
December 13, 2010 03:14AM
    
It seems that we're getting hung up on terminology. I don't know of anyone that refers to the removal of matrix to better expose crystals as "enhancement." Others factors such as color or luster may be enhanced by irradiation or a quick acid dip, etc. but to use the e word for removal of matrix seems to me to be a bit off base. I, for one, would rarely purchase an "enhanced" specimen but personally do all I can to make the specimen more aesthetic and appealing by removing unwanted matrix either away or adjacent to the crystal(s).

I personally like the specimens and would be thrilled to happen upon a shale layer loaded with the buggers!

Dana
avatar Re: Fake pyrite concretion?
December 13, 2010 10:09AM
Reiner,

you simply can't state things like that as fact without evidence. You should learn to use words such as "I believe" or "probably" in your replies.
Re: Fake pyrite concretion?
December 13, 2010 12:04PM
    
Living on top of concretion-prone geology, I've seen plenty of peculiar concretions that just don't look natural, but are. The Chinese pyrite concretions look like variations of some of the Ohio shale concretions found around here:



I have one that is more spherical than the one above, and with smaller pyrite crystals in bands around the concretion similar to the Chinese examples. It was allegedly found in one of the ravines around here. I need to ask the guy who gave it to me where, specifically, he found it.

I've posted my hamburger pyrite before, which I plucked from a ravine in Columbus:



Concretions in general are bizarre, and if you do a google image search you will find some really strange items prone to all sorts of conspiracy theories.

My sedimentary geology colleague told me that in general concretions are seen as a curiosity by geologists, and are not much studied. There is a general understanding of how they form but many specific forms are not well studied. I did a quick search on China Shale Concretions in the scholarly lit and there is some material there, just no immediate proof (images, etc.) that the Chinese pyrite concretions are natural and unaltered.

John K.
Re: Fake pyrite concretion?
December 13, 2010 04:54PM
Hi all,
I have never held one in my hands and all I know about them is what I see in the photos. So I am not stating anything here and not questioning if they are real or fake. I would still want to understand how such thing could have formed.

What I am questioning is if they should be called pyrite concretions. I don't think they are, because pyrite only makes thin parallel bands in the shale (btw, is it really a shale?). So, we have the rounded chunks of shale (with pyrite in them) sitting in the same shale? Or the matrix is a different rock?
Pyrite concretions in sedimentary rocks represent the accumulations of recrystallized pyrite that was mobilized from inside of the host rock. I don't see that mechanism at work here, because pyrite is not massive.
Also, the accumulations form where some space is available or as a replacement. Could those ball formations be some sort of a replacement? If yes, what could that be that those balls have replaced?

Large balls are well known from the residual bauxite deposits, but those grow from inside, just as the pyrite or other true concretions do. Those gibbsite balls are essentially the giant pisolites, that's how they get so well rounded. Again, I don't see that mechanism at work here.

What I see in the photos is the rounded chunks of a sedimentary rock with parallel pyrite bands (not unusual at all) incorporated in the newly formed clastic sediment.
Question to those who know what kind of black rock is the ball and the matrix: Could that kind of rock be rounded so smoothly or it would simply not survive the prolonged natural abrasion needed to become a ball?

And the last question: have anyone seen the ball's cross section?
avatar Re: Fake pyrite concretion?
December 13, 2010 07:11PM
    
Reiner

have you actually seen or handled these?

They may perhaps turn out to be fakes, but to me, they certainly don't look like it. There is no abrasion on them, they are plentiful and they are in a wide range of sizes. And regardless of that, they are all uniform in shape and habit. There certainly doesn't appear to be any artistic interpretation here.
Re: Fake pyrite concretion?
December 14, 2010 12:59AM
    
"because pyrite only makes thin parallel bands in the shale"... Michael, they are solid pyrite, you can't judge the actual structure from a photo, in fact, there are ones that have a lot more pyrite showing and not in concentric layers. If it is just shale in between layers of pyrite they would easily split along the shale. You do not see any fractured this way.
Re: Fake pyrite concretion?
December 14, 2010 02:10AM
    
OK for solid pyrite concretions with no matrix they are probably all natural (assuming no grinding has taken place to enhance the overall shape), for ones with matrix where some of the matrix has been removed to enhance the pyrite layers thus alter the appearance of a natural concretion they are probably enhanced.

Is that better Jolyon?
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