Quick Links : Mindat手册 The Rock H. Currier Digital Library Mindat Newsletter [Free Download]

主页关于 Mindat Mindat手册 Mindat的历史版权 Who We Are 联系我们于 Mindat.org刊登广告

捐赠给 Mindat Corporate Sponsorship 赞助板页已赞助的板页在 Mindat刊登广告的广告商于 Mindat.org刊登广告

Learning Center What is a mineral?The most common minerals on earth Information for Educators Mindat Articles The Elements The Rock H. Currier Digital Library Geologic Time

搜索矿物的性质搜索矿物的化学 Advanced Locality Search 随意显示任何一种矿物 Random Locality 使用minID搜索邻近产地 Search Articles 搜索词汇表更多搜索选项

Mindat手册添加新照片 Rate Photos 产区编辑报告 Coordinate Completion Report 添加词汇表项目

Mining Companies 统计会员列表 Mineral Museums Clubs & Organizations 矿物展及活动 The Mindat目录表设备设置 The Mineral Quiz

照片搜索 Photo Galleries Search by Color 今天最新的照片昨天最新的照片用户照片相集过去每日精选照片相集 Photography

Discussions

💬 Home 🔎 Search 📅 Latest

╳Discussions

💬 Home 🔎 Search 📅 Latest

Groups

Recent Images in Discussions

Techniques for CollectorsCleaning Pyrite

13th Oct 2004 16:03 UTCAndy K

Hi everyone..

Just a quick question.

I have a large mass of Pyrite which is quite tarnished. How do I safely clean this to get it shining again (or is this impossible).

Please.. I'm not a chemist so all those nasty chemical solutions will be no good so does anyone know how to do this with general household stuff (but above all safely).

thanks

Andy K

14th Oct 2004 08:06 UTCGunnar Färber

Hello,

put it in oxalic acid or in HCl both can help you.

Best Regards

Gunnar

14th Oct 2004 17:40 UTCalfredo

Peruvians, probably the biggest exporters of pyrite to the USA and Europe, give most of their pyrite a bath in HCl before export. (I don't know the concentration they use or time taken.) You could try the acid sold everywhere for use in swimming pools - In the USA that is often a mixture of HCl and phosphoric acid.

Cheers,

Alfredo

14th Oct 2004 19:17 UTCRob Woodside

Sodium Dithionite will remove iron stains and is commercially available. When Bob Jackson hits a new pocket of Pyrite at Spruce, the pyrite is usually covered in limonite and he doesn't know until a dithionite or HCl bath whether the pyrite below is dull or lustrous. The lustre, if gone, cannot be restored and is the difference between the specimen being worth tens of dollars instead of hundreds.

15th Oct 2004 05:21 UTCAlan Plante

Hi again, Andy

It would be helpful if you state where the specimen came from - and whether or not it is a matrix piece, the matrix important to the specimen. Knowing where the specimen came from, someone clicking in here might know exactly what you need to do for specimens from that locality.

Barring that, you might want to try some less aggressive cleaning agents first - like a scrub with a scouring powder that doesn't have anything harder than 5 on the Mohs Scale in it - then maybe some Super Iron Out if the scouring powder doesn't work.

With any mineral that is prone to rusting or tarnishing, a thorough drying is required immediately following cleaning - even if it is just setting the stuff out in the sun, or on a windowsill that is getting sun. So be sure to dry the pyrite after you get it cleaned.

Regards

Alan

15th Oct 2004 14:50 UTCsgibby

Hi,do u know a chinese powder? U just sprinkle it on your pyrite and brush it. That's it. Cheap and easy way and not harmful your pyrite. We use this in Thailand.

9th Nov 2004 16:46 UTCAndy K

Thanks everyone..

I actually got this from Lyme Regis in the UK (fell out of the cliff)

It's a bit massive but does contain some crystals..

Anyway.. more than enough idas..

Thanks again

Andy K

4th Jan 2005 21:58 UTCFranklin Roberts

Watch out when soaking pyrite in acids, it'll give off hydrogen sulfide gas (rotten egg smell) which is highly poisonous. A bad side effect of H2S exposure is its tendency to desensitize the sense of smell so that its concentration seems to be decreasing when in fact it could be building up to toxic levels in the room. Play it safe and do this outdoors.

Franklin Roberts

Austin, Texas

18th Jan 2005 01:02 UTCDave Baldwin

I don't want to worry you Andy, but the pyrite from Lyme and surrounding areas is quite unstable and very prone to decomposition. It will start to develop efflorescence, may crack and fall apart. You can reduce the decompostion by placing it in an airtight container and/or avoid damp atmospheres.

Incidently, this decompostion of pyrite ultimately destroys many beautiful fossils from Lyme Regis and Charmouth.

Dave

19th Jan 2005 09:27 UTCRock Currier

Dear Andy,

If you pyrite is not already shiny, I know of no way you can make it shiny except by polishing it with standard lapidary procedures. I have had good luck with cleaning pyrite with the commonly available Lime Away cleaner. I believe it contains phosphoric acid to some extent. If your pyrites are in pretty good shape but a little old and not as shiny as you remember them to be, try this product. Be sure to soak them in clean water thoroughly after using the product to be sure it has been removed from all the cracks in the specimen. It also works on chalcopyrite if it is not too far gone.

Rock Currier

19th Feb 2005 16:28 UTCPatrick Slavenburg

Hi,

following up on this discussion: I bought a Bulgarian chalco with galena and sphalerite. The Chalco is a large separate crystal, covered with probably limonite (mostly). I cannot use an acid bath for fear of damaging the other crystals (which are physically separated from the chalco. Could I try cleaning the chalco with Sodium Dithionite or Lyme Away cleaner by just covering that particular chalco crystal, or does it need to lie in some bath for hours and hours ?

The Chalco crystal is quite big: 3-4 inches diameter, and it has a perfectly etched 2 inch galena attached to it, hence my eagerness to see if I can get lucky with a lustrous (or at least colorful) chalco. If you would have any other suggestions I'd be very much obliged !

Thanks

Patrick Slavenburg

27th Nov 2005 23:32 UTCRock Currier

Sgibby

I know nothing about the Chinese powder you mention. Any information you could give me about it would be appreciated. It is difficult to understand what kind of powder or chemical that it might be that would quickly allow one to make pyrite shiny.

Rock

20th Dec 2005 09:17 UTCKeith Compton 🌟 Manager

If the discloration is only due to a little oxidation then perhaps this may help.

Why not try cleaning it gently wth a toothbrush and toothpast (whitening type) and tepid water. Then lightly rinse and dry thoroughly - and I mean thoroughly.

I have found that it will work in most cases and I have yet to find a pyrite / chalcopyrite specimen damaged in this way.

As many of these whitening toothpastes are now made in China perhaps that is the white powder referred to.

The toothpaste has not worn away my teeth - so it shouldn't wear away your Pyrite!!

13th Jan 2006 02:34 UTCben waitkus

what elements (periodic table of the elements) do you use to make pyrite

13th Jan 2006 13:46 UTCDavid Von Bargen Manager

See the chemical formula here:

http://www.mindat.org/min-3314.html

26th Jun 2006 02:51 UTCAl

I have just tried the toothpaste method and it works well without any damage to the pyrite.

21st Sep 2006 12:36 UTCPaul Stahl

Some safe substances I have been using to clean chalcopyrite of late are the commercially available extract of citrus peel general purpose cleaners available in all supermarkets. Soak the specimen for 3-7 days totally submerged in the liquid then scrub the specimen with a hard tootbrush before washing citrus extract off. After a good scrub rinse throughly in water and look at the shine on your specimen! Ive been using it for months with fantastic results. Even if you already have a high grade specimen you will notice a change.

26th Sep 2006 20:52 UTCPeter Haas

A 50 g/l (i.e. 5% w/v) solution of citric acid does the same job in just a couple of minutes.

1st Oct 2006 04:34 UTCGary Kutac

I have several pyrite 'Floaters' and Spheres similar to the German ones on page 11 of the pyrite gallery. These were found in North East Texas (many of them 1 -2 inches in diameter). They have a rust on the surface of the crystals. Is this removeable? My young son just wants to smash them (they are beautiful on the inside).

1st Oct 2006 05:24 UTCKyle Eastman

There are certain chemolithotrophic(rock-eating) bacteria that decompose sulfides and are known to destroy the luster of pyrite and other minerals.

I would suggest sterilizing all pyrite specimens with ultraviolet light or some other method before storage or display to prevent damage! Interestingly, similar bactera have been shown to produce the CO2 that goes into the formation of copper carbonates--thus the banding in azurite and malachite represents season patterns of bacteria growth!

An interesting web site: http://www.astrobio.net/news/article202.html

-Kyle

Go to top of page