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Fakes & FraudsIrridescent pyrite suns

2nd May 2008 22:51 UTCgeminerals

Hello,

I am a part-time mineral dealer/collector. At my recent show, I had some

irredescent pyrite sun's from Sparta, Illinois. They are brassy with lovely

blue/green/red hues. Another dealer had a flat of the more common less brassy and duller sun's that he was selling. He mentioned to me that mine had been treated with bleach to give them that appearance of irredescence. Is this true?

If so, I would like to be able to tell potential customers of this before they commit to buy.

Thanks,

Greg

3rd May 2008 04:32 UTCsteven garza

Dear Greg;

Not only is that true, besides making them prettier, it also makes them MUCH more susceptable to breakdown from moisture in the air. They have a considerable amount of marcasite intermixed (typical for shale pyrites) & the treatment seems to "turn on" the decomposition process. Except for those kept in "dry boxes", most that others have bought have deteriorated in 5 to 7 yrs, leaving a shelf/box full of crumbly gray-white powder & giving off LOTS of sulfuric acid fumes. I bought one from two wholesale brothers who told me, right up front, they were treated; within 1 yr, I started smelling the fumes being generated & after 4, I had nothing left. I bought the piece STRICTLY to have something to show people what happens to these specimens.

My suggestion: get rid of them & consider the loss the cost of education that's worth a LOT more!

Hope this helps.

Your friend, Steve

3rd May 2008 06:11 UTCgeminerals

Steve,

Thanks so much for the information; too bad as they sure are pretty. I will have to cull the one in my collection; I don't like the sound of sulfuric acid fumes floating around my cabinet full of specimens. Thanks for the fast response.

Best regards,

Greg

5th May 2008 18:16 UTCgeminerals

How exactly is this process done? Does it work for all pyrites? Also, the irredescent chalcopyrites from Sweetwater/Missouri; are they treated as well, or are they natural. Any info would be greatly appreciated.

Thanks,

Greg

15th Jun 2008 12:14 UTCKevin Farrell

That sucks. The "sun" that I recently purchased (attached pic) doesn't have the irridecent colors, but it does have a very slight smell. Not really sulferic (bleach?) or is this normal?

Marcasite content? I've heard of "pyrite disease" relating to marcasite. How common is this?

I have both pyrite suns and marcasite specimens that I've had more than 20 years with no sign of deterioration...

16th Jun 2008 03:59 UTCJustin Zzyzx Expert

Kevin,

that one already looks like it will go. Depending on your location and storage measures, you'll start to notice that the least shiney areas will get darker and darker, eventually turning into a powder, which will then turn white as it ages. Yum.

16th Jun 2008 12:37 UTCsteven garza

Dear Kevin;

Justin is right; it's JUST starting to go & you just have to wait a little longer & you'll REALLY notice the "sulfuric" smell. Once the process has started, it's pretty much a forgone conclusion that you are looking at the best it'll ever be, for the next few months.

As far as the other marcasites, it depends on what type rock it came from & location, as Justin also mentioned; to be honest, ALL marcasite specimens are a crap shot & need to be handled sparingly & watched carefully. You just never know WHICH will sit in your collection for 50 yrs & which will start to alter the day you get them!

I've found that most that come from a shale environment, as the Illinois suns do, will disintergrate anywhere from a few months to 10 yrs (though, THAT'S rare!); those that come from from a limestone that has SOME copper mineralization or metamorphic environment tend to be stable. Don't know the reason for the copper making them stable, but, as copper IS a botanical poison & sulphide-eating bacteria ARE plants, that might be a good reason, even if the Cu is in PPM.

Hope this helps.

Your friend, Steve

16th Jun 2008 13:36 UTCPaul L. Boyer

Copper kills alot of different bacteria as well as a lot of plants, but bacteria are not plants by any definition.

16th Jun 2008 13:37 UTCKevin Farrell

Thanks for the replies and info. Good to know (now).

That one's from Zigler Mine, Sparta, Illinois.

Shameless Plug: I think I'll do some education at the first meeting of the newly formed Hunstville Texas Area Gem & Mineral Society - see http://www.mindat.org/msgboard-15.html

Thanks again, Kevin

16th Jun 2008 14:21 UTCDan Weinrich Expert

Greg,

Regarding the Sweetwater chalcopyrites. Some are treated with an acid solution to bring out the color. Others though are completely natural. I have seen them freshly collected, in miners lunchboxes, that are beautifully iridescent.

Dan Weinrich

16th Jun 2008 21:20 UTCsteven garza

Dear Paul;

Read the following: "Once considered a part of the plant kingdom, bacteria were eventually placed in a separate... more"; I'm sorry that I didn't keep up on the reclassification, I grew up when they had JUST decided that was where they belonged. One of the points for putting them there, as I remember, was their sensitivity to CU, the same as algae, fungi, & most other plant species; one of the reasons they DIDN'T want them in plants is they also had some animal characteristics, such as mobility. I guess they finally decide a proper place for them.

Your friend, Steve

2nd Jul 2008 01:55 UTCMark Heintzelman 🌟 Expert

I know the idea of the presence of Marcasite in these formations is a persistent one, but according the data published in "Occurrence and Distribution of Minerals in Illinois Coals", C.Prasada Rao, H. J. Gluskoter, Ill State Geo. Survey, Cir. 476, 1973, X-ray diffraction studies determined these radial Iron Sulfide formations to be primarily Pyrite, no significant presence of Marcasite.

In the breakdown, Pyrite accounted for 23% of mineralization in these deposits, Kaolin, Quartz and "Carbonates" accounts for the other 76%. Observations of Marcasite made up only a portion of the last 1% of mineralization, along with Sphalerite, Galena, et al.

Steven has pointed to an observation I've made myself, in this case concerning those large cubic Pyrites which occur throughout Pennsylvania. Anecdotal as it may be, the ones which occurred within the coal field regions proved to be unstable. All but one I've owned eventually exhibited some degree of decay, however not a single one from outside the coal regions ever have.

I only have four of these Illinois "suns" in my personal collection, two golden in color (one is "iridescent") and two silver colored. I too have had them for many, many years now, and thankfully none of them have so far shown any evidence of decay (lucky me I guess).

MRH

2nd Jul 2008 04:31 UTCAlfredo Petrov Manager

A lot of collectors are under the impression that if it decomposes rapidly it must be marcasite, not pyrite. But, as Mark points out, that's not true. There is great variability in the stability of both marcasite and pyrite. I've had very bad luck with pyrites from all types of sedimentary rock, but my pyrites from high-temperature hydrothermal veins (Bolivia, Peru, Japan, Washington...) seem to be completely stable. Marcasite the opposite - my hydrothermal vein marcasites have all crumbled, but some good crystals from a Czech coal mine seem to be stable. I'm sure other peoples' experiences will vary greatly.

A dry atmosphere helps, but even that is only a delaying tactic; the air is never dry enough to stop the decomposition completely.

With regard to iridescence, note that ANY mineral becomes iridescent when coated with an extremely thin layer of another substance (like a tiny drop of oil spread out over a rain puddle). If Nature hasn't already created this layer for you, you can do it yourself by any number of different chemical reactions, but it is the thickness of the layer, not the type of reaction, that will determine whether you get iridescence or not.

2nd Jul 2008 04:41 UTCsteven garza

Dear Mark;

Your report said, "In the breakdown, Pyrite accounted for 23% of mineralization in these deposits, Kaolin, Quartz and "Carbonates" accounts for the other 76%. Observations of Marcasite made up only a portion of the last 1% of mineralization, along with Sphalerite, Galena, et al"; it DOESN'T say where they took those samples, which layers or at what point in those layers the samples were taken, or, how many samples were evaluated. Here's what I found: mild HCl DOES attack marcasite, like crazy, while pyrite seems to hold up quite well. I've used samples from one deposit to prove this point to beginners, bcs the marcasite & MOST of the pyrite grow separately into each other. A sample of marcasite will be GONE in about 1 day, while the pyrite (bcs it DOES have some marcasite in it, too) will have subtantially dulled faces, but, little else (if you want a piece of this to try, let me know). When I tried this on a pyrite dollar, I was left with a MASSIVE display of slightly pyritey "swiss cheese", which means there MUST be some marcasite in them. Something else to consider: what if the supposed (you won't convince ME there's only 1%; would someone sacrifice a piece & do a probing?) 1% breaking down CATALYZES the pyrite breakdown, in a slower reaction environment? Much like calcite/aragonite specimens tend to do, quicker than calcite or aragonite specimens, alone, do?

I, too, have "suns" that have lasted a LONG time (over 50 yrs), BUT, under the same conditions (they were kept together), I've had MANY that have "died" within 4 yrs. BTW, after my FIRST result of that experiment, I trashed ALL specimens that smelled the slightest breakdown. Wish I had done it on specimens from other locations.

Your friend, Steve

2nd Jul 2008 16:07 UTCMark Heintzelman 🌟 Expert

Hey Steven,

It always bugged me that I've heard so many contradictory "facts" about these Pyrite "dollars", so last year I decided to try and find some research papers which addressed them. This was the only descriptive report I could find with particulars on the subject, and not for lack of trying! :) It is perhaps more generalized than I would like, and it covers/describes a rather wide region, noting little variation. Perhaps this is a troubling oversimplification, but not having conducted the research in this report myself, I cannot say. The breakdown of mineralization noted is a region wide assessment, the low accounting of Marcasite does not indicate it was not concentrated (i.e. in these concretions), but only indicates it's presence in the region is uncommon. I would think however, that a scholarly approach to describing these concretions was made, which included a reasonably large subset of specimens taken from various sites and at various levels, etc. I personally prefer that these details be remarked upon in the report, describing the subset used for any study, but sadly this report does not. So it is only an assumption on my part that some diligence was taken in developing this description. Considering the source I would think it a reasonable assumption though.

As Alfredo confers, there are any number of occurrences where the local Pyrites are particularly unstable, without being caused by inter-development with Marcasite. I don't want to argue with your own observation, just noting what has been reported to have been observed concerning the regions mineralization and these concretions in particular.

Luckily, I learned early on to separate pieces showing signs of Pyrite disease from the rest of my collection, and I still have a separate "ward" for those pieces, some still worth retaining even after 20 odd years. It is always sad though to have to commit a decent specimen to the trash, but I've had to do it (kicking and scratching all the way to the bin)!

MRH

8th Jul 2008 03:04 UTCWes Gannaway

Hello all, I have had 2 "suns" from the Baldwin Mine in my collection since 1988 and both are doing well. One is still in shale (was removed, cleaned and glued back on) and the other one is out of matrix and in a drawer. I have (had?) one of the marcasite nodules from France for about 4 years and it is on a shelf in my shop, just a pile of white melanterite powder. Same thing for a specimen of pyrite from the Rainy Mine at Monte Cristo, Snohomish County, Washington; a white pile. It all depends on the conditions during crystal growth. I would guess that FeS +O2 can eventually equal FeO and SO2. All of our pyrites and marcasites will do this after an undetermined period of time. My question follows Alfredo's comment. Do these suns grow under some sort of higher temperature setting? Is the coal Anthracite due to metamorphism? etc. Is the shale more of a slate?

23rd Jul 2008 01:26 UTCTed Kepling

I have some nodules I found in black shale from central Illinois were I live . Found these looking for fossils . Several exibit much irredescense in blue,green,red ,gold , and are very heavy . The best ones I have just sitting on a shelf , others are outside . There has been no change to them after two years . I don`t know the mineralogy but they are very nice and interesting . I have only seen similar on ebay as being from Russia , they called them irridescent chalcopyrite concretions .

23rd Aug 2008 15:31 UTCAlysson Rowan Expert

I have had a number of shale and chalk marcasites degrade over the years, and the only way that you can preserve them (before they start to decay) is to keep them both dehydrated and oxygen free. I have managed neither.

You may be able to stabilise the specimen as follows:

Wash thoroughly in a solution of baking soda (to neutralise any acid), possibly soaking for a few days. Then a long soak in clean water, and a soak in distilled water.

Dry thoroughly in a warm place and then either soak in oil (not recommended) or varnish with something like crystal mount (a clear, toluene-soluble varnish).

Of course, there are no guarantees, and in one of my specimens, the decay was kicked off by the soak.

I have lost a couple of rarities from a very unusual site to this. In the case of a rather fine micro fan cluster, the whole process of decomposition took about 5 days - before I could even take decent photographs.

12th Sep 2008 23:53 UTCPaolo Malesci

Decay occurs alsoo in large and solid pyrite crystals but it's require a different lack of time for different specimen of the same locality too.

We have observed differences in the behaviour of pyrites of Rio Marina Mine, Elba Island, Italy, related to the matrix: on lamellar hematite matrix are more stable that on granular pyrite matrx.

Despite of care they are not eternal: at the University of Florence Mineralogical Museum all the specimen of the ancient collection (late 18th century) had been lost and so also the greatest share of the hystorical (Foresi & Roster) Elban collection.

26th Nov 2008 22:03 UTCJason Evans

So, are all pyrite suns with irridecence bleached, or can some have natural irridecence? my sun has it and now im worried

27th Nov 2008 11:41 UTCKevin Farrell

I don't see or smell any change in the one I purchased last April...

2nd Dec 2008 19:18 UTCPeter Hargis

So, are ALL irridescent pyrite suns treated? If so, I found an eBay seller selling "irridescent pyrite suns" in which he claims they have never been treated. See his response to me...

"Dont worry about my clients or inventory it WILL NEVER CRUMBLE now I must get back to my three e-bay stores and 20-50 packages daily made.Good luck with buying on E-bay bye bye now"

It seems a little condescending to me (maybe it's just me), and I was wondering if I could post the name of his eBay store to let people know he is selling treated minerals without acknowleding it to his customers. Or is this something that is not allowed/recommended. Thank you.

2nd Dec 2008 20:08 UTCAlfredo Petrov Manager

Iridescent pyrites (and of course chalcopyrites) might be mostly treated, but not necessarily, and I doubt there is any way to tell for sure whether one is treated or naturally iridescent. If you follow the philosophy that a suspicious object or person is innocent until proven guilty, then you must be careful. I personally would not "name and shame" a specific culprit unless I had some pretty strong evidence, both out of a sense of fairness and a fear of lawsuits.

The iridescence on some minerals is caused by an extremely thin coating of another substance on the surface, like the rainbow effects created by a drop of oil on a puddle of rainwater. Nature can do this at certain early stages of weathering, an effect that is lost at later stages when the alteration film gets too thick.

If I saw a whole flat of pieces that were all equally iridescent, I'd be highly suspicious that they were treated; the naturally iridescent pieces tend to be quite non-uniform in degree of iridescence.

2nd Dec 2008 20:13 UTCPeter Hargis

Thanks for the clarification. You're right, better to let it work itself out than to wrongly accuse someone.

5th Dec 2008 16:52 UTCAlbert Mura

McGee, I would not buy anything from someone who answers you like that. I have a collection of over 1300 pyrites collected over 30 years and the fact is certain ones will decompose while others don't. Pyrite suns as neat as they are will eventually decompose as stated above. Also as Alfredo says some pyrite specimens can have a natural tarnish but it might be only on part of the crystals. There are pyrites like the Spanish cubes that are very stable and I have never noticed any decomposition on any of the ones I have. Al

5th Dec 2008 17:01 UTCAlbert Mura

Just one other comment, as I have been collecting pyrite for 30 + years, I do not remember iridescent pyrite sun's showing up on the market until recently. Many years ago I went to Sparta and saw some of the miners and the suns they collected and I do not remember any that were iridescent. Of course that's not to say they having found any recently.

5th Dec 2008 18:26 UTCMaggie Wilson Expert

Hello McGee - pyrite issues I cannot address, but the response from the Ebay seller is considerably less than comforting. I've been in retail sales (sewing machine sales and service in the past and currently am customer service rep for manufacturing equipment) and have also dabbled in the Ebay market. When I read the seller's remarks, I get "oh-ohs" loud and clear.

First, the flippant and dismissive tone diminishes your concerns. Yelling at you via USING CAPS is also bad form. Finally, the seller goes on to elevate his position by claiming to have so much Ebay business, that he must of course be legit.

Sure, the product may be bona fide. But it is my not so humble opinion that the seller could use some lessons in PR. Remarks like those do not help his case.

Maggie

27th Nov 2011 08:58 UTCjake

This is a true Iridescent pyrite sun. They are rare in nature. Out of a thousand pyrite suns i have only found 3 or 4. I have found once you clean them they loose the most of the iridescent look. The ones on Ebay are done with chemicals, camera tricks and lighting tricks. The best way to keep them in this state is not to clean them and seal them with clear polyurethane spray. If you have a normal pyrite sun like 99.9% of them out there toilet bowl cleaner, a wire brush work great, and a dental pick will do the job. If you want to use less toxic chemical use homemade laundry soap and dry with acetone. Pyrite suns are not mascrites, some with break there's no way to stop it about 4 out of 100 will break its a fossil not all are solid some have internal crack or weak spots that when you clean them they will break or break down later own on there own. All my pyrite suns have been mined in the last four years. They have been pulling these things out for a hundred years all in Randolph county in many different locations within that county. So can only vouch for recent pyrite suns.

27th Nov 2011 11:55 UTCRock Currier Expert

Jake,

What mines are currently producing the suns? What is the largest pyrite "sun" you have seen.

Rock

27th Nov 2011 15:15 UTCAlbert Mura

Jake, there was analysis done, I believe by Steve Chamberlain and reported at the Rochester Symposium, that some of the suns do contain marcasite. Al

27th Nov 2011 22:17 UTCJake

The gateway mine is currently the only remaining mine producing pyrite suns and they have at least 4 more years left likely more. They did open another mine called prairie state I don't know if it contains pyrite suns or not it's fairly new and the distance is away from know producers. The biggest one yet I have got was about 5 1/2 inches in diameter. As far as some containing marcasite I can believe that, that would explain why some just don't make it. Was that study done on only randolph county pyrite suns or did it included the china and other suns found world wide. I will definately read that report any info on theses things would be great since barely any info exist. thanks

27th Nov 2011 23:14 UTCAlbert Mura

Hi Jake, I believe the study was only done on the Randolph suns. I will try and find the writeup for the study.

8th Dec 2014 18:40 UTCpnjfm

I have cleaned literally hundreds of suns. Some are are irredecent some are not. Some will clean very well and remain strong for years. The ones that do breakdown are usually more because of faults along the sun lines during growth. Most which had the strong sulfur smell have lasted me three years with no more signs of deteriation after white dust was removed and cleaned still remain shiny and sparkly. I use no coatings.

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