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Techniques for CollectorsCleaning or Polishing Pyrite

18th Nov 2018 11:54 UTCSabrina Nicholson

Hi, everyone. Could use some good advice about how to bring the shine back to this pyrite sphere that I have. I have this really nice pyrite sphere that I purchased recently that was supposedly mined in Peru. I have no idea what type of iron pyrite this is, only the approximate origin.

I should preface this to say that I'm not a geologist, and have little knowledge in the field of mining and minerals, but am seeking professional advice.

I've been researching online to try and come up with the best method of polishing this pyrite. I read an article on here (Cleaning Pyrite) and came away pretty confused after reading at least 10 different suggestions on how to safely polish a pyrite specimen. I'm hoping there's a general consensus among you.

I don't have a garage, a hose, or particularly like the idea of messing with chemicals like Hydrochloric acid or Oxalic acid because I'm totally inexperienced.

My question is - is there something safer (besides using a brush w/ whitening toothpaste) that I can buy on Amazon or get at Home Depot to safely brighten & clean this sphere? I don't want a silvery finish. I wanted to restore the gold shine to it. Someone recommended using Simple Green or Lime Away to me. Another post that I read suggested Citric acid. I'm worried about experimenting and unintentionally ruining the sphere. Will any of the above mentioned agents work to bring back the shine? What non-toxic method (if any) will bring back the golden "display-type" shine, as shown in my photo (with the black background, below)? I've already asked the seller and he didn't seem to be sure. Many thanks.

The photo of the pyrite with the black background was the sales listing photo. The other photos (with the white background) is how the sphere sort of looks now. The photos had to be enhanced a little bit because of poor lighting.

18th Nov 2018 11:55 UTCSabrina Nicholson

18th Nov 2018 12:50 UTCKevin Hean

Hi Sabrina. Don't use Hydrochloric acid, you may end up with a "Stink Bomb" that clears the neighbourhood. :-))

I would try rubbing the Sphere with Leather rather than Cloth because cloth will hook on all the sharp edges.

You can use a Metal Polish that contains a powder, a metal polish that you would use to polish brassware, knives and forks etc.

Some tooth pastes contain a "polishing powder", ie: a toothpaste that is not a Gel Type.

Try it out on a small section first to see the result.

I notice that your sphere is made up of many small crystals so you shouldn't have too much trouble.

All this is of course is dealing with the outer surface, to do inside the nooks and crannies you will have to do what Keith suggested and use a tooth brush.

Pyrites are known to decompose, so do yourself a favour and do some research on storage.

Good Luck....

18th Nov 2018 15:04 UTCReiner Mielke Expert

"Pyrite as you know has a perfect cleavage" No, pyrite has a poor/indistinct cleavage see: https://www.mindat.org/min-3314.html

18th Nov 2018 16:17 UTCKevin Hean

Apologies to the Mineral community.:-) Thanks Reiner. Edited out.

18th Nov 2018 16:58 UTCAlfredo Petrov Manager

The pyrite sphere is most likely from Peru, where the pyrite is pretty stable. And Peruvians do clean their pyrite with hydrochloric acid (but that's for crystal specimens, not after cutting).

However you clean and/or polish it, I'd keep it away from human hands afterwards; handle with gloves. Natural human skin chemicals don't seem to be very good for pyrite luster.

18th Nov 2018 19:57 UTCSusan Robinson

Do not wash in water, and stay away from anything acidic. If you are successful at bringing back its brighter sheen, then try to keep it as dry as possible. Having it in a moist, damp environment will likely cause "pyrite disease", and once started, it's nearly impossible to stop, and will, over time, destroy the specimen.

18th Nov 2018 21:20 UTCThomas Lühr Expert

The 'Waller solution' aka SIO / IO brings back the luster within seconds (literally) and prevents the 'disease'.

18th Nov 2018 21:31 UTCAmir C. Akhavan Expert

You can try to "dry brush" the sphere.

It sounds silly, but I've successfully cleaned a few slightly tarnished pyrites and marcasites by patiently brushing them with a dry old toothbrush - after a while they got shiny again. Give it a try before you resort to chemical treatments.

As Alfredo said, the human skin is not nice to pyrite, so I wear gloves while I clean them.

19th Nov 2018 00:15 UTCSabrina Nicholson

Hi, I didn't have any luck finding "Waller solution." Is that the brand name, or is it the type of cleaning solution?

Do you know of a link or site where I could get it?

Thank you, Amir.

19th Nov 2018 00:24 UTCAlfredo Petrov Manager

Sabrina, "Waller solution" is a name used in Germany for a buffered sodium dithionite solution recipe, similar to the commercial brand called "Iron Out" in the USA.

19th Nov 2018 01:22 UTCThomas Lühr Expert

For those who don't have access to "Iron Out"

Here is the original receipe of the Waller solution from Mineralogical Record 11 (p.109) as pdf-file

19th Nov 2018 13:13 UTCSabrina Nicholson

I just ordered a leather shammy, polishing gloves, and a tube of Simichrome 390050 “All Metal Polish (cream) polish.”

It’s supposed to be for non-ferrous metals, so I guess it won’t work on iron pyrite.

More to the point: what else can I buy commercially in the U.S. that will actually work??

19th Nov 2018 13:15 UTCSabrina Nicholson

Here’s a link to the polish: Simichrome 390050 All Metal Polish Tube - 1.76 oz. https://www.amazon.com/dp/B0002YUQ4E/ref=cm_sw_r_cp_tai_5wR8Bb8STJ952

19th Nov 2018 14:26 UTCSabrina Nicholson

There’s only one video on YouTube regarding polishing iron pyrite, and it involves using muriatic acid, which didn’t really show decent results. In fact, the acid literally ate away the rough pyrite specimen. I’ve yet to see anyone post an actual helpful video about how to bring back the shine of a polished/finished iron pyrite piece. I wish that someone would just make a short YouTube video on how to polish a (finished, not rough) iron pyrite piece, to bring back the gold shine using an easily accessible non-toxic powder or polish. Alternatively, they could make one video on polishing a smooth pyrite piece, and then make another video for brightening up a rough pyrite piece. So many people would find it helpful if there were more safer, easier methods, you know?

19th Nov 2018 15:10 UTCWayne Corwin

Sabrina

If you want to polish the finished, not rough crystals you need to get some 'wet or dry' sand paper, start with 1200 grit, use wet, and if you can find any finner 'wet or dry' paper finish with that. In just about a minute your color will come back, it doesn't take much to remove the oxide surface.

You can find the 'wet or dry' paper at almost any automotive parts shop.

No acids or chemicals!

Fast & cheep besides!

19th Nov 2018 15:28 UTCSabrina Nicholson

Thanks, but I’m really worried about scratching the surface with sandpaper or using water.

I could really use a method that is non abrasive and gentle, but really effective in bringing back out the shine (like you see in the sales photo with the black background).

... Isn’t there some commercially available products (in the U.S.) that are available on Amazon that I can use?

Is there some kind of polish or powder for ferrous metals like pyrite? Just need a straight answer.

I don’t have any special lapidary equipment. Just these two hands and polishing cloth.

Can someone please answer that? Thanks!

19th Nov 2018 16:11 UTCDavid Von Bargen Manager

You can get some polishing powder at a hardware store (or at least order it through them)

For instance

https://www.acehardware.com/departments/automotive-rv-and-marine/auto-tools-and-maintenance/polishers-and-buffers/28983

Your biggest problem would probably be removing the polishing compound (it will get in the cracks/crevices on the sphere).

The process has to be a bit abrasive or else you won't get the tarnish off. Polishing powders will not scratch the surface because they are extremely fine grained.

19th Nov 2018 16:12 UTCKevin Hean

Sabrina, I am sure you will succeed with the Simichrome and the leather, I too would be a bit frightened to use an abrasive , after all you are only trying to remove the tarnish on an already polished ball.

Here are some some powders that you may prefer.

https://www.amazon.com/s/ref=nb_sb_noss_1?url=search-alias%3Daps&field-keywords=stone+polishing+powder&rh=i%3Aaps%2Ck%3Astone+polishing+powder

19th Nov 2018 17:00 UTCSabrina Nicholson

Thank you so much for getting specific! All I needed was a push in the right direction with a brand name. The suggested techniques are always welcome too. :)

19th Nov 2018 21:07 UTCSabrina Nicholson

Dremel just told me to absolutely not use their compound.

19th Nov 2018 22:11 UTCKeith Compton 🌟 Manager

You could try using any silver polish and soft lint free cloth. You will find most hardware shops will stock a variety of silver cleaners (eg Silvo) which is a liquid. When finished simply wipe clean.

Try on a small section first.

If it doesn't work well enough at least you will be able to clean your silver dinner service.

Whatever cleaning product you use, I feel that the tarnish will most likely return after a short while and you will have to repeat the process.

20th Nov 2018 00:10 UTCSabrina Nicholson

So confusing. From what I’m reading most silver polishes won’t help a bit. I can’t risk damaging this piece, but when that Simichrome polish arrives, I’m going to try and spot treat the under side of another large pyrite to see what happens. With any luck, I’ll have great results and can post pics.

21st Nov 2018 19:44 UTCThomas Lühr Expert

Just to show the effect: One half of that pyrite specimen has been dipped into a puffered dithionite solution for 30 seconds.

The second photo shows a specimen that already in the decomposing process (note the fissure in the lower left cube). Since the treatment (soaking for some days), a few years ago, it is unchanged and the decomposing stopped (the future will show for how long)

Thomas

21st Nov 2018 22:55 UTCSusan Robinson

Rob Waller was a conservator who worked at the Canadian Museum of Nature in Ottawa, Ontario. He wrote a book on the techniques of mineral conservation, and also had an article in the Mineralogical Record magazine (Volume 11, no. 2, 1980, pp. 109-110) on the chemicals needed to create the de-rusting solution that many of us now use to clean minerals. After publication, many collectors commonly used the term "Waller solution" for the chemical mix, and using it on the minerals was to "Waller them."

I hope the readers find this information helpful,

Susan Robinson

22nd Nov 2018 02:36 UTCSabrina Nicholson

Thank you so much Thomas, Keith and Susan. I think I'll try the Simichrome polish. I think I'll need an toothbrush in case it gets into the golden "vugs" inside the sphere. I bought some white cotton polishing gloves to keep the oils from my hands off of it.

Being such a newbie to this, any ideas where I can buy this "Waller solution?" Does it make it silvery finish or will the pyrite keep its gold coloring? Is there some other name that it goes by? Would love to know the cleaning technique with the solution. I take it that you're supposed to dip it in a solution and leave it there? If so, for how long? Or, do you buff it on and then off with a leather polishing cloth? Thanks again.

12th Jan 2019 21:37 UTCTina Williams

Hmmm. I too have some pyrite to clean. Where might one find this “Waller solution” you speak of?

I’m wondering if it would help this piece. Pyrite looks to be oozing out of the cracks in this one. Found in North east Tennessee on a mountain, 20 pounds about 14 inches long quartz. I love it but the pyrite is dull.

Thank you!

12th Jan 2019 22:03 UTCThomas Lühr Expert

Tina,

"Iron Out" is a commercial equivalent of the Waller Solution, available in the USA.

For you it is the best to use those. As far as i know there are more products of different composition, but all called Iron Out.

The powder should be the right one. Look at the listed ingredients, to be sure: "sodium dithionite" or "sodium hydrosulfite" (different names of the same stuff) should be mentioned.

Thomas

12th Jan 2019 22:51 UTCBob Harman

TINA,

I hate to respond to your postings, but from this posting and your previous postings on cleaning specimens, you seem to be way to quick on the cleaning trigger!

Other than a good washing and rinse, cleaning mineral specimens, in my opinion, should become an art. Look critically at each specimen to see what realistically (!!) can be accomplished. Can the example be realistically and meaningfully improved, both aesthetically and, if $$$ is involved, from a monetary point of view ??.

For your 20 pound example, do you think you can really clean that up using a whole lot of iron out or something else? What do you plan to do with it? Do you plan to display it on a shelf or put it in your garden? In my opinion, using a lot of iron out on that specimen will really make it look no better.

For me, be realistic, leave it as it is, putting it on display in your garden. It is a yard and garden rock. CHEERS.....BOB

12th Jan 2019 23:02 UTCDoug Daniels

Agree with Thomas on what the stuff is, and with Bob on the need to clean it using the stuff. Note that the pyrite is not "oozing out" - it just happens to be exposed. Now, a 20-lb specimen is kinda big, and may need a lot of Iron Out. Note also that it isn't that pleasant a substance to work with. And you would have a lot of used solution to dispose of, as well as a lot of rinse water. Looking at the photo, it might be a good candidate for the hammer-and-chisel method; then maybe Iron Out. Also, using the Iron Out may initially clean it, but may trigger some reactions that don't show up until later, especially if it hasn't been rinsed enough.

12th Jan 2019 23:50 UTCBob Harman

Cleaning a specimen like you show, is far more than changing its colors. It is aesthetically improving it! Will it be improved....no, not in my opinion. CHEERS.....BOB

13th Jan 2019 00:46 UTCThomas Lühr Expert

Tina,

I agree with the two guys, your piece is way too large for such treatment.

You should follow to Doug's suggestion and break it apart, using hammer and chisel. With a bit luck (and skills) it breaks along the pyrite layer. Choose the best piece (maximal fist sized) and give it the treatment. The rest leave as it is.

You don't have to be worried to trigger a process of decomposing. In the contrary, the alcaline components will eliminate any sulfuric acid. The acid is product of decomposition that hastens further decomposition - a downward spiral. Iron Out prevents that. But, as Doug wrote, all the chemicals must be good washed out by a good soaking in clear water.

Thomas

13th Jan 2019 02:47 UTCTina Williams

Thank you everyone for the information. I prefer keeping things in their natural state when possible. I was not going to treat the whole thing in iron out I was just wanting to see if I could brighten the pyrite a little.

I do not look for monetary value in any of my pieces I just love the beauty they have.

I’ve worked with super iron out powder for quite some time and I am familiar with the safety precautions and rinsing regimen that must be used with it.

I understand nothing is “oozing out” that’s just the way it appears and I was trying to describe it in case you all could not see where the Pyrite was in the picture because it’s dull.

Tina

13th Jan 2019 05:19 UTCアーロンベリル

Lovely specimen if you like seeing minerals in the geological setting they were formed in! Maybe try cutting the rock in half lengthwise. You might expose an entire surface of pyrite.

13th Jan 2019 19:05 UTCTina Williams

Thanks Aaron. I’ll think of something.

31st Mar 2019 13:59 UTCAarti Kalro

I've used a diluted silver polish to brighten my pyrite , and I use it quite often. It does contain some amount of HCL. I am not a specialist , but this has worked fine on all my pyrite. I leave it to soak overnight at times, but I would suggest you check it at regular intervals to make sure your specimen is doing ok !

My ratio is about 1 tsp for 1.5 cups of water. You can experiment .

Good luck. !

31st Mar 2019 16:49 UTCDonald B Peck Expert

Pyrite is insoluble in HCl, so I would not worry too much about the small amount in silver polish.

31st Mar 2019 18:38 UTCKevin Hean

Hi Donald,

As Kids, living on the Witwatersrand, there was always a Dad giving one of us some, of what they called, Iron Pyrites from a gold mine, for us to make stink bombs with by adding it to HCL.

As you would know a test to see if Lapis Lazuli contains Pyrite or is man made with little flecks of brass, a drop of HCL smells of rotten eggs on Lapis with pyrite.

I wonder what happened to Sabrina who started this Thread with her Pyrite Sphere.

31st Mar 2019 19:24 UTCAlfredo Petrov Manager

As lapis lazuli/lazurite contains sulphur itself, and is decomposed even in diluted acids, it is likely that the stink of H2S is coming mainly from the lazurite itself rather than the pyrite.

1st Apr 2019 18:55 UTCDonald B Peck Expert

I once suggested that hydrogen sulfide could be generated by the action of HCl on pyrite . . . and it was gently pointed out that such is not the case. This morning I have been reading research papers, etc. I spent some time with http://www.vitorge.name/pierre/publis/04des_vi.pdf , and if I read it correctly, pyrite + HCl does react to a very (edit: extremely) small degree, but the reaction products do not include H₂S (someone who is a better chemist than I may correct me on this.) However, perhaps a weathering product from pyrite may produce H₂S, I am not sure on that. BTW, pyrrhotite and HCL will produce H₂S. The website, marulla(dot)com, http://marulla.com/mineral-solubility/, includes rather complete tables of mineral solubility. It indicates that pyrite is not soluble in HCl but is readily soluble in HNO₃.

1st Apr 2019 20:08 UTCKevin Hean

Thanks Donald, I was only about 10 or 12 at the time And as I said they called it Iron Pyrites or fools gold, so heaven knows exactly what it was,

all we were interested in was the stink :-)

Looks like Alfredo is right as well about the H2S originating from the Lapis and not the Pyrite, and I was told this in a Gemmological lecture,

anyway you live and learn.

1st Apr 2019 21:07 UTCDoug Daniels

Kinda interesting how this thread has wandered a bit. First was cleaning pyrite, can HCl be used. Apparently, if it is a solid, robust, unweathered specimen, then maybe yes (even Dana says no reaction to HCl). Now maybe, if the specimen is starting to decompose (which may not be obvious), perhaps reaction with HCl will give H2S; you only need about 5 ppm to detect it with your smell sense (go much higher, your sense of smell is then deadened to it.....). Not sure why lapis was brought in....if natural, then the lazurite contains sulfur, and may react with HCl (but what concentration is needed?) And, if it's an artificial lapis... And to further deviate, I remember as a young lad, having had several chemistry sets. In some, there was a little bottle of an iron sulfide, as I recall sub-named iron pyrites (mind is rusting). Used mainly with sodium bisulfate to create H2S (the rotten eggs smell).

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