FMF - Friends of Minerals Forum, discussion and message board

[Matt_Zukowski]

I apologize in advance if the ideas posted here have been rehashed a million times before.

I have some perfect, undamaged cubes on matrix with interesting growth/etched features. The cubes have good luster and I'd like to keep it that way. I would like to hypothesize cleaning with acetone after any handling (and perhaps periodically) to keep the luster nice and the features undegraded. I put forth this idea because:

* A major reason pyrites degrade is a microbially mediated oxidation by Thiobacillus. Acetone should kill, disolve, and help remove and bacterial agents.

* The main limiting agent is inorganic oxidation is water. Acetone is a drying agent and should, at least for some time, return the surface to a dry state.

* Acetone has a neutral pH and is more likely a reducing agent than an oxidation agent.

* Acetone is inexpensive and available in any hardware store.

What do others think?

[Carles Millan]

Hi!

I do NOT have a deep knowledge of this topic, but I love those pyrites and own more than ten specimens from Navajún, a half of them on matrix.

The older was acquired in 1978 (more than 30 years ago!), and there are others purchased in the early eighties. All of them have been kept in a showcase without any measure of protection, and all are in perfect conditions. So I guess there is no need of using acetone.

Just an advice. Don't allow any contact of the matrix with water.

I'm sure other members of the forum, especially in the Spanish side, may provide much more data.

[Carles Millan]

Excuse me, I forgot it!

My Navajún pyrites have been touched with my fingers dozens of times. It's not difficult even to notice my fingerprints on their surface. Although I never clean them, no damage can be seen on the crystal faces after many years.

If you liked it, you can see several of my specimens at https://www.mineral-forum.com/message-board/viewtopic.php?t=397&postdays=0&postorder=asc&start=0 and following pages.

[Jordi Fabre]

Matt,

I'm not in Spain currently, so I can't answer you properly. Just on case that you can read or translate Spanish language, I suggest to you to read this topic published in the Spanish Forum where you can find a lot of infos: https://www.foro-minerales.com/forum/viewtopic.php?t=249

Anyway, probably some other Forum members will help you. At worst, I will do it myself at my return, next week.

Jordi

[chris]

Hi Matt,

I prefer to use ethanol to fix M. Bacillus. It is less aggressive than acetone, and less likely to damage something.

Regarding pyrite and its chemistry, I see no reason why acetone should damage it. Acetone is even recommended to clean specimens coated with glaze. If you want to be cautious, try first on a small unexposed surface and see want happens after some weeks.

Christophe

[Jordi Fabre]

Don't use Acetone! The majority of Pyrites from Navajún are glued (consolidated), so if you use Acetone you will have a nice combo of separate cubes ;-)

Please try to read the Spanish text of this link:
https://www.foro-minerales.com/forum/viewtopic.php?t=249

Maybe some Spanish member can read it and translate a digest to English language?

Jordi

[Peter Megaw]

On top of Jordi's comment, don't forget Acetone is nasty stuff and highly flammable...Use with care with good ventilation. If you inisist on using a solvent to clean them, start as simply as possible with undiluted alcohol. I have heard of people using microscope lens wipes to remove fingerprints from specimens...very local application, immediate evaporation (active ingredient is isopropyl alcohol) and no significant contact with the glue. Might be worth a try... test one on a low-end specimen first of course.

[Matt_Zukowski]

Wow - thanks all for the thoughtful replies. I knew after having several good conversations with Jordi at Tucson (I am the guy from Alaska) that I had made a good connection.

I am gathering that maybe the best thing to do is nothing. I may use some acetone or alcohol on the xtal faces only, dabbing with a rag or Qtip and making sure that the the fluid does not reach the matrix.

Thanks all.

Peter, any use of acetone will happen outside. I once got this STINKY halite from Searles Lake with this tenacious, pink to black, tar-like organic material that smelled like a combination of burning rubber and very old dead fish. I soaked that thing for two days in acetone (outside) and still couldn't get it all off. That halite remains outside in a shed, and now that the snow is melting I am going to go up and see how it did.

And Charles, nice picts.

[Peter Megaw]

Crush it up and use it on the driveway while there's still ice that needs melting...it will always stink.

[Matt_Zukowski]

Excellent suggestion - if it still stinks then that is probably the best use for it.