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Fake pyrite concretion?
Posted by Reiner Mielke
Dana Slaughter December 12, 2010 03:32PMHi Reiner,
I've examined these at the 2010 Tucson Show and they appear completely legitimate to me. I saw several examples that were of poor quality and doubt that one would take the time to manufacture ho-hum specimens. Several major US dealers had examples and I haven't heard of any suspicious commentary. Still, with the increasing propensity to enhance or manufacture specimens one really has to be on alert.
Albert Mura December 12, 2010 03:39PMHi Reiner. There are a million of these Chinese spherical pyrite concretions on the market, I've seen some as large as bowling balls. Most likely too many to fabricate. In any case, pyrite forms round concretions from many many places. Many form in sedimentary rock that was still soft enough for crystallizing pyrite to form a sphere. In China alone there are numerous locations for spherical crystallized pyrite. Al
Reiner Mielke December 12, 2010 04:15PMFrom what I have seen pyrite crystallizes either radially in a concretion or in concentric layers. These crosscut the the concretion! Since the vast majority of Chinese are poor, it is probably worth their while to make these. I would like to see a photo of one in situ.
Albert Mura December 12, 2010 04:27PMAs any person who has tried the lapidary arts with pyrite knows it is an extremely messy material to work with. Even though many Chinese are poor I would assume that they would want to get maximum return for their efforts and you surely are not going to get that with pyrite specimens ( and that comment coming from a pyrite collector!),
Reiner Mielke December 12, 2010 04:49PMMost Chinese earn less than $500US per year. I don't know what these fetch in China but here is one for sale on e-bay for $135US. http://cgi.ebay.com/2-3-Sparkly-Gold-Striped-PYRITE-BALL-Concretion-China-/130446796690?pt=LH_DefaultDomain_0&hash=item1e5f3c2792 Seems to me at that price it would be well worth the effort no matter how dirty a job.
Reiner Mielke December 12, 2010 05:10PMLooks to me like it is made from a rock with pyrite layers. You simply cut the rock into squares and round the corners on a grinding wheel. Assuming the matrix is softer than the pyrite you would then remove some of the matrix with a wire wheel. No polishing necessary so it would be very easy to do.
Edited 1 time(s). Last edit at 12/12/2010 05:14PM by Reiner Mielke.
Reiner Mielke December 12, 2010 05:30PMEither that or you could get that effect by sandblasting, which is probably the way they would do it considering how much of it is being produced. This would also make then appear more natural since a wire wheel would leave scratches in the matrix.
Not knowing what the matrix is but if it were calcareous you could also accomplish this with acid.
Edited 1 time(s). Last edit at 12/12/2010 05:32PM by Reiner Mielke.
Jolyon & Katya Ralph December 12, 2010 05:42PMI have one which has no abrasion damage to the pyrite, there are sharp pyrite crystals appearing in bands poking out around the sides of the "egg".
No idea whether it's natural or faked. But some of the suggestions being made here are plainly wrong.
Reiner Mielke December 12, 2010 06:02PMHas anyone seen one in matrix? If these are coming out by the hundreds then there must be a centralized source. I bought a made in China compressor for $99 and a sandblaster for $15, I imagine they are even cheaper in China so it is not unreasonable to assume they can afford a sandblaster. Nevertheless I think it is important to establish if these are natural considering how much is being asked for them and how many there are.
Adam Kelly December 12, 2010 06:32PMIn my humble opinion they are natural.
There are too many, too cheap for me to believe they are fabricated.
I have worked as a jeweler for about fourteen years, and details are my work.
I saw absolutly no "refinishing" anywhere on any of these.
Rock Currier December 12, 2010 06:34PMIf these are being made or enhanced, I don't think the Chinese need much in the way of equipment to make or enhance them. All that would be needed to make the pyrite stick out in a prominent fashion is a stiff wire brush which would remove the black shale and it would not hurt the pyrite. If they were not oval or round concretions to start with, I think a hammer could break them down to what ever size was desired. I suspect they be mostly natural concretions based on the variety of sizes that are available. 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.
Crystals not pistols.
Edited 1 time(s). Last edit at 12/12/2010 06:35PM by Rock Currier.
Adam Kelly 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.
Adam Kelly December 12, 2010 06:54PMProbably in similar fasion to the azurite and malachite concretions from La Sal area of Utah.
Just a different soup.
Pyrite link... http://www.mindat.org/photo-185225.html
Edited 2 time(s). Last edit at 12/12/2010 06:58PM by Adam Kelly.
Howard Messing December 12, 2010 07:01PMHere are some pictures of several more that I own of various sizes:
and something similar from New York State:
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.
Reiner Mielke December 12, 2010 07:49PMThanks 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.
Reiner Mielke December 12, 2010 08:24PMEnhanced 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.
Colin Robinson December 12, 2010 08:56PMPyrite 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!
Reiner Mielke December 12, 2010 10:15PMOK 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-)
Matt Neuzil December 13, 2010 02:14AMjust 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
Dana Slaughter December 13, 2010 03:14AMIt 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!
John Krygier December 13, 2010 12:04PMLiving 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.
Michael Hatskel December 13, 2010 04:54PMHi 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?
Ian Jones December 13, 2010 07:11PMReiner
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.
Albert Mura 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.
Reiner Mielke December 14, 2010 02:10AMOK 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?
Alfredo Petrov December 14, 2010 02:52AMApart from matrix-free specimens like alluvial nuggets, meteorites, etc, I suppose almost all mineral specimens have been "enhanced" by judicious removal of some matrix, cleaning off of unwanted films and crusts, etc. They don't look the same as they did when still embedded in the wall of the mine! But the word "enhance" seems to have acquired undesirable connotations among collectors (despite the fact that most of their specimens have been "enhanced" in this sense). So we are faced more with a semantic problem than a mineralogical problem. Perhaps we need two different words, one for desirable enhancements and another for undesirable enhancements, bearing in mind that "desirable" and "undesirable" are going to be frequently endlessly debatable and that the boundaries change with the fashion of the times and with the culture.
Asians do tend to like to give matrix an artistically sculptured appearance - as for example with the chipping of the white marble matrix of the pink Vietnam spinels. I don't particularly appreciate that technique myself, but we mineralogically scientific Westerners are only a small segment of the market for such stuff, so we can avoid buying them, but that's not going to have much influence on the custom.
Dean Allum December 14, 2010 06:50PMI don't see a problem with a natural evolution of these pyrite concretions. I have seen numerous concretions (Kettle Point, Ontario, Colorado River, Utah) with layers of hematite stains. As these weather out of their matrix, they are often concentrated by natural processes (such as rolling down hill).
If you bury these in an organic rich, reducing environment for a million years, the chemical reaction produces pyrite, just as it does for the pyrite "dollars" found in the midwest U.S. coal mines.
Robert Knox December 14, 2010 07:00PMI'm looking forward to perhaps picking up one of these "new" Chinese pyrites in Tuscon this year.
Because this type of nodule is formed in sedimentary deposits, the banding could be explained by the differences in the makeup of the individual layers of the sediments.
I have in my collection a "spherical" pyrite in black shale matrix from China, that is entirely made up of cubic crystals. Sorry no photos, but it is 3cm big(the nodule) with the individual crystal face of 2mm.
Reiner Mielke December 15, 2010 12:48AM"Because this type of nodule is formed in sedimentary deposits, the banding could be explained by the differences in the makeup of the individual layers of the sediments. " If that were the case then the banding would not be resticted to round spheres ( concretions) but extend into the matrix. Also concretions are not a product of sedimentation but later crystallization of minerals around a nucleus be that a fossil or mineral grain.
Roger Lang December 15, 2010 08:33AMFolks,
IMHO they are all natural .. i have had some of those in my hands and i have seen a picture of them in situ in a mudstone/shale (but do not remeber who showed me the picture). To me they are nothing unusual re formation ...
There are single "balls" as well as "bread leafs" and double "eggs" etc.
Georg Graf December 16, 2010 10:19PMHi All,
for me these Pyrite concretions are natural.
I imagine, the Pyrite grow in mud at the borderline of two stata of fluid with different O2 content, Fe content ore other chemical/physical conditions. And this borderline sink and go up by the time; maybe with the rainfall, summer heat ore other climatic conditions.
My wife comes from Shanghai. Since I met her, I say (, if she can not hear it): "If You have to do with Chinese, think like Chinese." - But in this case, I think, the P. concretions are natural.
And an other important point, which has nothing to do with mineral collecting: If China is econmically developed like the Western World, the economy of the Western World will not break down! Like the British economy broke not down at the end of the 19th century, when Germany and Austria became technical and economical developed like England!
Inhonest dealers You find all over the world. - There are many fakes of and fraudulent Trilobites from Morocco. The Morocco people learnt it from white dealers, how the make a trilobite fake!
Greetings from Thale near Goslar
Phil Richardson March 21, 2012 10:38PMGreat question Eric,
Unfortunately, my initial observations is that some are going to be problematic. A little over two and a half years ago Mike New, of Top Gem in Tucson, imported thousands of Chinese pyrite concretions. Solid pyrite concretions, with no shale banding, and the appearance of crystalized surfaces. (Top Gem had been importing them for a number of years prior to this, but not anything like this shipment for quantity.) The bulk of the pyrite concretions that I chose from were round, with a sizable percentage flattened discoid shaped. I was careful, sorting through hundreds, and picked out ones with minimal flaws, and specifically no cracks.
Now several years later a number are starting to have issues. Out of 12 flattened discs, ranging in diameter from 4cm up to 6.5cm, 5 now have radial cracks with one severely cracked. All of the spherical pyrite concretions that I picked out, under 5cm in diameter and showing prominent crystal faces surrounding the exterior surface, are fine. They show no cracks, discoloration, nor do they 'smell'. Now I cant say the same thing for the large ones that I chose. I picked out several exceeding 10 cm in diameter. Out of three, two are starting to turn. They are developing a darker patina, and have several areas with lighter discoloration appearing. Picking them up, and smelling them, they are developing a noticable odor. I have removed the big ones from display and storage with other pyrites. What I did notice, is that the larger diameter pyrite concretions have smaller crystal faces showing on the surface, and more resemble 'scales' instead of cubic faces.
Upon close inspection, with a hand lenses, I can find remnents of shale matrix down in crevices between crystal faces on most of the Chinese pyrite concretions. It has only been recently, in the last two years, that I started noticing the shale banded pyrite concretions. I did pick up two feeling that they were legitimate natural specimens, similar in occurence to those I already had. I have not yet had any issue with those.
Sorting through so many pyrite concretions, I was fortunate to see several which had been broken in half. The interior showed bright 'pyrite' colored material with a fibrous radial pattern. It was similar in appearance to the interior sections that I have seen in French marcasite concretions. I am not sure if that type of structure has any relevance, since crystalized pyrite, when broken, has a semi-concoidal fracture.
Ben Grguric March 22, 2012 07:25AMHi Phil,
It is quite common in many of the occurrences of these spherical or spheroidal pyrite concretions that the internal structure includes zones which are pyrite intergrown with some marcasite. Examples I've looked at under the reflected light microscope were from Dover, England and several places in the Goldfields and Pilbara province in Western Australia. This marcasite component is quite distinctive in reflected light and I suspect this mineral is the main culprit responsible for the concretions falling apart in a damp atmosphere.
Robert Knox April 11, 2012 08:47PMI happened to come across a Sino-American couple that import these concretions from family in China. This was at one of the outlying venues at Tuscon this year. They informed me that these things are NOT completely natural. They had dozens of both spherical and egg shaped nodules with rings, spirals, even diagonally patterned ones. They did state that they have been decorated and shaped by man. Even though they were VERY cheap, I did not buy one.
John Krygier June 01, 2012 10:15PMHi all,
This thread has been going on so long that an entire research project on similar iron-sulfide shale concretions in central Ohio has been completed (since I last posted) by an undergraduate student in our department. The project was presented at a GSA meeting a month or so back, and the abstract is below. The link goes to a GSA page with a big PDF download with information and data for the geologically inclined. The research focused on the stages of development of the concretions, their organic origins, and their mineral composition (pyrite and marcasite - which develop in a complicated manner - see the PDF at the GSA link below). Eric's plans to continue studying the geomicrobiology of the concretions in graduate school. I'm not a geologist (I work with them) but this was a fun project to follow.
Marcasite and pyrite in the concretions (reflected light microscopy (RLM)):
Some SEM images from one of the concretions:
Below is an image of one of the flatter concretions cut in half. A spherical specimen was cut, but I don't have a picture at the moment.
GSA Abstract & PDF download: http://gsa.confex.com/gsa/2012NC/finalprogram/abstract_202972.htm
IRON-SULFIDE CONCRETIONS OF THE OHIO SHALE: GLIMPSES OF DEEP SUBSEAFLOOR MICROBIAL ECOSYSTEMS OF THE LATE DEVONIAN
MUMPER, Eric, Department of Geology and Geography, Ohio Wesleyan University, Delaware, OH 43015, firstname.lastname@example.org and FRYER, Karen H., Department of Geology and Geography, Ohio Wesleyan University, Department of Geology and Geography, Ohio Wesleyan University, Delaware, OH 43015
Recent interest in black Devonian shales for natural gas exploitation has brought shale research into new importance. At the same time, advances in the understanding of deep subseafloor microbial ecosystems have revealed that microbes play a more pivotal role in geologic processes than ever imagined. The convergence of these two areas provides an excellent opportunity to reexamine enigmatic concretions of the Ohio Shale. The Huron member of the Ohio Shale is distinguished by the presence of carbonate concretions. These concretions vary considerably in size and differ in composition from the host rock. Their origins have been questioned since they were first described in 1873. Current models attribute concretion formation to abiotic mineral replacement of organic substances. However, smaller, iron-sulfide concretions inhabit the same horizons and are less well studied. Iron-sulfide mineralization has been attributed to biotic processes and may be connected to the presence of the larger carbonate concretions. Iron-sulfide concretions have been collected from three sites in Delaware and Franklin Counties in Ohio. These samples were investigated using reflected light microscopy, scanning electron microscopy, and energy dispersive x-ray spectroscopy. Based on morphology, composition and size, the iron-sulfide concretions have been categorized into four different stages of paragenesis. These stages correlate well with known microbial zonations of deep subseafloor environments. Understanding the microbiological processes at work in the creation of black Devonian shales may shed light on how to exploit modern microbial systems to develop sustainable sources for carbon fuels in the future. GSA North-Central Section - 46th Annual Meeting (23–24 April 2012)
D Mike Reinke July 21, 2012 09:00PMHoward, if that is museum quality, what museum already has one?? To me, tho I'm a novice, comparatively at this, hollow means fake. Slag has air bubbles, rocks are solid, except for geodes. I thought of a basketball dipped in clay. Where in Kansas? Are there more? Jsome ideas for you...ust
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Copyright © mindat.org and the Hudson Institute of Mineralogy 1993-2017, except where stated. Mindat.org relies on the contributions of thousands of members and supporters.