Discussion of best and safest ways to clean and prepare minerals. http://www.mindat.org/msgboard-19.html Sun, 19 May 2013 13:45:20 +0000 Phorum 5.2.15a http://www.mindat.org/forum.php?read,19,28758,294206#msg-294206 http://www.mindat.org/forum.php?read,19,28758,294206#msg-294206
You are not restoring a shiny surface to your minerals, but rather adding a coating of oil to them. Many people think this is cheating, but many don't. Its up to the individual. The down side is that dust and dirt will stick the the specimen more than in its natural state, and you will have to clean them more and reapply the oil.]]> Rock Currier Mineral Cleaning and Preparation Sat, 18 May 2013 20:58:59 +0000 http://www.mindat.org/forum.php?read,19,28758,294200#msg-294200 http://www.mindat.org/forum.php?read,19,28758,294200#msg-294200 ToniH Mineral Cleaning and Preparation Sat, 18 May 2013 19:47:04 +0000 http://www.mindat.org/forum.php?read,19,294031,294158#msg-294158 http://www.mindat.org/forum.php?read,19,294031,294158#msg-294158 Try hydrogen peroxide. The 3% solution that they sell in drugstores works great. Just submerge it and let it bubble, might take a few days till the reaction stops. I have not found anything that is damaged by it. Used it on mineral specimens and fossils.
Cheers,
Jim]]> Jim Gawura Mineral Cleaning and Preparation Sat, 18 May 2013 03:50:12 +0000 http://www.mindat.org/forum.php?read,19,294031,294147#msg-294147 http://www.mindat.org/forum.php?read,19,294031,294147#msg-294147 Rock Currier Mineral Cleaning and Preparation Sat, 18 May 2013 01:08:25 +0000 http://www.mindat.org/forum.php?read,19,294031,294100#msg-294100 http://www.mindat.org/forum.php?read,19,294031,294100#msg-294100 Steve Hardinger Mineral Cleaning and Preparation Fri, 17 May 2013 13:08:15 +0000 http://www.mindat.org/forum.php?read,19,294031,294031#msg-294031 http://www.mindat.org/forum.php?read,19,294031,294031#msg-294031 AJ Luzier Mineral Cleaning and Preparation Thu, 16 May 2013 18:13:57 +0000 http://www.mindat.org/forum.php?read,19,292761,293632#msg-293632 http://www.mindat.org/forum.php?read,19,292761,293632#msg-293632 Reiner Mielke Mineral Cleaning and Preparation Sat, 11 May 2013 00:56:58 +0000 http://www.mindat.org/forum.php?read,19,292761,293509#msg-293509 http://www.mindat.org/forum.php?read,19,292761,293509#msg-293509

If you want to remove Na-Nitrate from the matrix you could use Ethanol to wash it out without damaging the Cu-compounds. But please be careful and try it first on a small piece first


Good luck

Holger]]> Holger Klapproth Mineral Cleaning and Preparation Thu, 09 May 2013 16:28:44 +0000 http://www.mindat.org/forum.php?read,19,293098,293507#msg-293507 http://www.mindat.org/forum.php?read,19,293098,293507#msg-293507

Ascorbic acid would need to incubate on the species for a longer time to have any effect at all. Ascorbic acid is a reductant that would reduce Mn⁴⁺ to Mn²⁺+ - and Mn²⁺ is then dissolved. But here we are talking about weeks not minutes. I am currently trying to remove black coatings from Clara fluorites. Peroxide failed there and so did Citrate. So I went to something rather brutal - Ammonium bifluorite: [en.wikipedia.org]. That is a kind of "weaker" hydrofluoric acid - for details see Wikipedia. This (5% w/v) takes about a week to turn the black to brown and another week to loosen the coating. Naturally if your samples are on a matrix etched by that it does not make sense. It also removes quartz coatings if you are very patient.

I would try ascorbic acid and patience.....

Best Regards


Holger


P.S. Ammonium bifluorite is very dangerous to use. Not as dangerous as HF but still noting to be used in the kitchen]]> Holger Klapproth Mineral Cleaning and Preparation Thu, 09 May 2013 16:23:21 +0000 http://www.mindat.org/forum.php?read,19,293098,293268#msg-293268 http://www.mindat.org/forum.php?read,19,293098,293268#msg-293268 Well, I did find some things that would remove it - but they removed the rest of the specimen too - and the unwary collector was not safe either!:

Happy hunting

Tim]]> Timothy Greenland Mineral Cleaning and Preparation Mon, 06 May 2013 18:35:20 +0000 http://www.mindat.org/forum.php?read,19,293098,293267#msg-293267 http://www.mindat.org/forum.php?read,19,293098,293267#msg-293267
thank you very much for support. I did the acid test Holger proposed, but it didn`t work. Normally the solution goes from yellow, yellow-green into brown, if the Mn-coating is brought into a soluble state by the citric acid. The acid has not shown any effect. Unfortunately the specimens seem to be not that bad... . I try to attach three images, just to give an impression.

Thank`s a lot
Hans-Peter]]> Hans-Peter Schröder Mineral Cleaning and Preparation Mon, 06 May 2013 16:59:49 +0000 http://www.mindat.org/forum.php?read,19,293098,293251#msg-293251 http://www.mindat.org/forum.php?read,19,293098,293251#msg-293251 i ran into the same problem with a couple of older campylite specimens from Dry Gill a few years ago. I tested some procedures with only limited success because the manganese oxides are commonly not only a surface coating (which could be removed with a suitable complexing agent) but are impregnating the campylite crystals. Hydrogen peroxide AFAIK breaks up to water and oxygen when in contact with manganese oxide - the latter being a catalyst for that reaction so there is no chemical but only mechanical effect because of the small oxygen bubbles which are generated.
Holgers idea of ascorbic acid or also citric acid could be worth of checking out - maybe you can try on a small sample which you may be able to sacrifice to test it. With iron oxide coatings this works well on phosphates as successfully tested with chinese pyromorphites (also with dithionite, but again, this works on iron oxides). Never ever HCl with Mn oxides - chlorine gas is produced and may lead to severe hazard ... and it ruins the campylite as well. I don´t know what phosphoric acid will do to the campylite ... i used it for several iron stained specimens with good success as long as there are no carbonates which will be dissolved.

In sum, you may have to check on a lesser sample and i would try out the ascorbic/citric acid option first.
If you can spare a small specimen and send it to me i could try here in the lab ....

Best regards
Roger]]> Roger Lang Mineral Cleaning and Preparation Mon, 06 May 2013 14:47:05 +0000 http://www.mindat.org/forum.php?read,19,293098,293171#msg-293171 http://www.mindat.org/forum.php?read,19,293098,293171#msg-293171

the black stuff could be manganese oxides. This could be treated with hydrogen peroxide.

In case you want have them inspected first - bring a piece to Set. Marie.


Best Regards


Holger


P.S. as I just saw other people recommend ascorbic acid (vitamin c) for that trick. If you know someone in BASF - they used to sell the stuff for less than an Euro the kilo to employees.]]> Holger Klapproth Mineral Cleaning and Preparation Sun, 05 May 2013 21:12:53 +0000 http://www.mindat.org/forum.php?read,19,293098,293101#msg-293101 http://www.mindat.org/forum.php?read,19,293098,293101#msg-293101 Rock Currier Mineral Cleaning and Preparation Sun, 05 May 2013 09:14:02 +0000 http://www.mindat.org/forum.php?read,19,293098,293098#msg-293098 http://www.mindat.org/forum.php?read,19,293098,293098#msg-293098
maybe somebody may help to fix a problem I have with some Dry Gill specimens. A few days ago I was lucky ( ? ) to purchase some flats with Dry Gill mimetesite, collected some decades ago in the Dry Gill mine underground. There is this ugly black coating covering some really nice crystalls. Is there a chance to get rid of it, without damaging the specimens or , beware, damaging myself ? Thank you very much. And best regards to Great-Britain.]]> Hans-Peter Schröder Mineral Cleaning and Preparation Sun, 05 May 2013 08:46:36 +0000 http://www.mindat.org/forum.php?read,19,292761,292761#msg-292761 http://www.mindat.org/forum.php?read,19,292761,292761#msg-292761 Hi everybody:

there are a few mines in the northern coast range of Chile, that host Cu chlorides. Itself Cu chlorides has no problem from weathering in desert environment.

I would like to know how can I preserve atacamite, anatacamite, paratacamite xls that grown on rocks that contains nitrates, altered clay, and iron oxydation (mainly limonitic matrix).

How can I stop the deliquescent process? Do you know any techniques & product that could be applied on this kind fo matrix?

thanks for your advisements

maurizio dini]]> maurizio dini Mineral Cleaning and Preparation Wed, 01 May 2013 00:19:32 +0000 http://www.mindat.org/forum.php?read,19,186968,292594#msg-292594 http://www.mindat.org/forum.php?read,19,186968,292594#msg-292594 Tim Jokela Jr Mineral Cleaning and Preparation Mon, 29 Apr 2013 18:01:04 +0000 http://www.mindat.org/forum.php?read,19,186968,292400#msg-292400 http://www.mindat.org/forum.php?read,19,186968,292400#msg-292400 You mention 'marcasite association w/ hydrocarbons' made a light finally go off in my brain-duuuh! I've seen that. Walking the Lake Michigan beaches, there are lots of rocks that have small cavities of oil in them, or drier tar. A few years ago I picked up a softball sized broken rock w/ a pyrite lined cavity, but solid with tar. I recently cleaned the smaller chip, and it is lined with dazzling blades of marcasite. I gave the bigger chunk to a friend for his yard, now I need it back!
But how do you clean out the tar? I soaked it in gasoline, WD40, simple green, hot water, a few other chemicals, yes, it stinks, and it took a long time. Soaking overnight only made slow progress each night. Is there an easier way? Doesn't sound like it...
John, your stuff sounds cool. I may be out your way next month-ish! Can't plan anything right now...

Mike]]> D Mike Reinke Mineral Cleaning and Preparation Sat, 27 Apr 2013 17:55:26 +0000 http://www.mindat.org/forum.php?read,19,292033,292165#msg-292165 http://www.mindat.org/forum.php?read,19,292033,292165#msg-292165 It sounds like you don't really have all that many to trim. The most time consuming part of using a trimmer is usually adjusting the distance between the blades so that they fit snugly against the specimen before you start cranking to increase the pressure on the blades. This involves backing off the blades so that you can fit the rock between them and then cranking till they are snug against the rock and then start serious cranking. Sometimes the blades will start to "walk" on the specimen rather than bite firmly and unless the "walking" stops at an acceptable point you have to back the blades off reposition the rock and start over. It is the backing off the blades and snugging them up again that takes all the time. There are trimmers, at least one I know of, a commercial brick/concrete block trimmer that has a crank mechanism that will quickly do this adjustment and can save you many hours of time if you do a lot of specimens, which apparently is not your problem. So I think the advice you have thus far gotten is OK. If the specimen you have is of high value, then most of the time you will not want to subject it to a trimmer at all, but rather use a diamond blade to cut away the offending matrix and then use pneumatic hammers/chisels of one size or another to remove the saw marks if they offend you or the ultimate customer/owner. But it sounds like you have been doing this for quite some time, and are able to judge when and when not to use a sledge hammer, trimmer or rock saw. I'm sure we have, all at one time or another, used a rock trimmer on a tough rock to try and obtain a nice specimen and have kept increasing the pressure on the rock until it "exploded" and sent the sought after crystals exploding out of the trimmer to bounce off walls or ceiling before hitting a concrete floor. A lot of successful trimming is to be able to judge from experience the likely outcome and to know when to stop.]]> Rock Currier Mineral Cleaning and Preparation Wed, 24 Apr 2013 20:48:17 +0000 http://www.mindat.org/forum.php?read,19,149266,292101#msg-292101 http://www.mindat.org/forum.php?read,19,149266,292101#msg-292101 Dessicant can help, but just before it starts. Afterwards you can try to remove internal humidity and acid with a bath in alcool, but in my experience I can't assure it works. Furthermore, If the specimen is internally damaged it can easily break up and disgregate.

Luca]]> Luca Baralis Mineral Cleaning and Preparation Wed, 24 Apr 2013 06:58:10 +0000 http://www.mindat.org/forum.php?read,19,290796,292097#msg-292097 http://www.mindat.org/forum.php?read,19,290796,292097#msg-292097 I wanted to thank everyone who has replied so far, for taking the time to do so.
I had also found that Mineralogical Research Company sells the bases that I originally posted about. They are a good source!
My inquiry was in response to an older friend who was seeking to upgrade their displays, and I volunteered Mindat as THE community to contact.

Continued input is welcomed, as their project is ongoing.

Thanks again,
John O:)]]> John Oostenryk Mineral Cleaning and Preparation Wed, 24 Apr 2013 02:36:48 +0000 http://www.mindat.org/forum.php?read,19,186968,292096#msg-292096 http://www.mindat.org/forum.php?read,19,186968,292096#msg-292096 Regarding the oil factor- Funny thing that! It was today, after Tim's post assured me of the nonresidual state, and I was sorting my reply issue, it kinda clicked that oil would 'fix' that 'light aromatics evaporation' issue that results in the prolonged odor from WD-40. Thanks for the confirmation.
I also concur- WD-40 does eventually dissipate totally- which would necessitate further application- just like any'protectant'. Whereas, as you say, the oil finishes the situation... Priorly, I just hadn't been able to take/make the full "leap of faith" with the heavier(than wd40) oil. It is pending,LOL.

I am currently drip drying after the WD-40 a batch of material that was a basketball size chunk of 100% intergrown stalactitic Linwood Mine marcasite. The decomp odor was really strong in some areas- so correct in nothing to lose:) Dang is it crazy intricate!
Incredibly complex, porous intergrowth. Within the innumerable openings, are innumerable small to tiny scaleno calcites... Its sorta like looking at a human vascular system replaced by a dripping and xtlizng FeS2...
The problem has occurred in past, in some more densely packed pieces where the water rinse leaves water trapped behind some calcite growth, and then oxidation converts to rusting stains. It definitely trashes the appearance, and while I see no way to fully get away from the entrapment, trying anyway! This big chunk already was majorly contacted throughout (how big was the parent???)from blasting. I ran it through a trimmer to open it up more for draining(Pieces are still big.) I have used a space heater set on high to flash as much water off before immersing in WD-40. Interesting too, no thermal damage to the calcites observed so far. (I wouldn't try this stunt on anything you weren't will to lose...) My thinking was hot water for final soak/rinse which promotes evap, then to hot dry air to continue the evap, aided by heat expansion of openings, which would possibly also allow some improved penetration for WD-40 next. Granted, that is prolly just positive thinking(coefficient of expansion being pretty tiny and of nanoshort duration when 'quenched' by the oil).
That initial trapped rusting on this batch, was very minimal compared to volume of success. More results as they become evident.
This will be a part of my 'proposed' and no doubt ridiculously long in images, lil report on your process~

Anyone want some INSANE stalactic/xtline camera fodder, micro/thmb Marcasite xtls? PM me for trades or whatall. It HAS been fun monkeying with it so far! Nuff bout that portion...

My correlation epiphany came from material from the southern edge of UMV type deposits just N of me. First portion was that the crystals were in exposed vugs in rock that was being immersed repeatedly for extended periods by extra scummy flood waters of the Mississippi River. That rock was dumped over 20 years ago. Anything below flood level that was unstable was just a reddish stain... And then there would be a cluster of stable xtls! WTH? Occasionally there would be gooey bitumin on rocks. I thought it was sloppy seal coat asphalt from the adjacent road, till splitting a boulder produced both gooey tar and light oil, with a nice pyrite cluster inside it! That got the seed to growing on hows and whys... It was timely that you had recently described your successful application... Following all that, I happened to make a huge find of intergrown pyrite and marcasite from a clay deposit in a regional quarry. I had a ridiculous quantity to sort out and THAT was when I decided to test the idea in full. I had mostly stable stuff, but some was clearly bad and some was shifting... So plenty of guinea pigs!
I guess you could say the rest of the story is becoming 'history', the WHOLE good kind, and not the disintegrated BAD kind...
Yes, obviously, in retrospect, your hypothesis on reduction and environment do make sense:) Good stuff!
More details eventually of course...
Thanks!
~JO:)]]> John Oostenryk Mineral Cleaning and Preparation Wed, 24 Apr 2013 02:24:04 +0000 http://www.mindat.org/forum.php?read,19,186968,292093#msg-292093 http://www.mindat.org/forum.php?read,19,186968,292093#msg-292093
Trouble with just WD40 is that it will eventually evaporate and you will be back to square one. Of course you can always reapply the WD40 but it stinks! Believe it or not motor oil does not smell nearly as badly as WD40 and lasts forever ( eventually converting to tar). I also came up with the idea of using oil because I noticed that marcasite associated with hydrocarbons are much shinier and less "weathered". Besides that the chemistry makes sense, no sulphide can oxidize under reducing conditions which the oil provides. Also the mess that pyrite disease makes is a lot worse than a bit of motor oil.]]> Reiner Mielke Mineral Cleaning and Preparation Wed, 24 Apr 2013 00:43:21 +0000 http://www.mindat.org/forum.php?read,19,292033,292084#msg-292084 http://www.mindat.org/forum.php?read,19,292033,292084#msg-292084 I have had an eventful day! I was able to secure one of these beasties today that is new, still in a shipping case(chisel tips are flawless)but for a used price.
As to volume of use~ hmmm- I don't know quite how to qualify that-LOL..
I am not doing commercial volume- I guess that would be safe to say. 10 or 20 pieces a month would = a crazy amount of local good luck in a year? So not that much...
I am in NW IL, and messing with sedimentary stuff mostly...
In field I try to reduce by sledge or 14" gas saw, Barites, calcite, sphalerite and cleavage vs breccia vugs etc... Kinda tricky ya'know?~but for close in I would rather bring it home big and work it down in patience. I avoid huge crossgrain breaks, but some bigger pushes with grain I don't mind. Trim saw and knippers etc... Chems..
I forsee some TN geode matrix- in near future, it is harder by a bit- but still not all day everyday! (Although if someone wanted to hire me doing mineral prep somewhere- I'd like to talk!:) The stuff is FUN!

All that aside- any info(experience or anecdotes) you could relay, I'd love to hear it~! These have been around for quite a while. Surely you know some things about them?!

I just got done going through our Geol Dept one-it had/has some issues, and I can see where it could have been beefed up, to better operate. I have a background in mechanical maintenance, millwright stuff etc. so do intend to tune mine prior to running it... Any pros or cons would be great to consider.

Those external springs, could actually have safety cables run thorugh the centers... I have personally experienced several flying garge door springs- live!! Scary stuff! The modern torsion version is far safer, but I see no application here, unfortunately.

Don't worry, if you say they suck- I won't be offended:)
I have had good success with a long run of stuff with the borrowed dept unit, post tuneup... I am pretty sure I have a sound purchase, and I truly can't afford a big zuber. If nothing else- this will get me through till better economics arrives someday:)
Look forward to your reply~
Thanks,
JO:)]]> John Oostenryk Mineral Cleaning and Preparation Tue, 23 Apr 2013 23:49:12 +0000 http://www.mindat.org/forum.php?read,19,186968,292079#msg-292079 http://www.mindat.org/forum.php?read,19,186968,292079#msg-292079 I do agree with the positive applications! I didn't really worry about being 'branded as being in the crazy camp' :0
I say that with simple humor intended- poking fun at myself!
There was no insult intended and I believe I have ammended the misunderstanding adequately.
Hope you understand-Have a good day:)
~JO:)]]> John Oostenryk Mineral Cleaning and Preparation Tue, 23 Apr 2013 23:05:41 +0000 http://www.mindat.org/forum.php?read,19,149266,292078#msg-292078 http://www.mindat.org/forum.php?read,19,149266,292078#msg-292078
Cheers!

Maggie]]> Maggie Wilson Mineral Cleaning and Preparation Tue, 23 Apr 2013 22:58:43 +0000 http://www.mindat.org/forum.php?read,19,149266,292077#msg-292077 http://www.mindat.org/forum.php?read,19,149266,292077#msg-292077 I'm glad you brought it to my attention- I should have waited till I had more time to post a better rendition of what I was trying to convey...
...Figures- I spent 4 times as much time trying to sort it out~ack!
Thanks for the understanding:)
~JO:)]]> John Oostenryk Mineral Cleaning and Preparation Tue, 23 Apr 2013 22:57:36 +0000 http://www.mindat.org/forum.php?read,19,186968,292075#msg-292075 http://www.mindat.org/forum.php?read,19,186968,292075#msg-292075 Several things to report for you:)
First- I certainly respect you! I have always enjoyed your friendly, positive, and detailed comments. I’m very serious about that and I do value your presence on Mindat!

2) AH-- I knew you were associated with Reiner- now I know how;) You DO know him!
I am very honest, and so I also understand righteous dismay(yours.) Very sorry about that!
I absolutely meant no disrespect, nor trolling, nor anger or anything negative at all!
I have ammended both posts to hopefully more clearly convey myself. I had posted to both threads so that the initial good news would be found in both places.
Really, I thought it was quite innocuous, as it was as anecdote about myself and learning- not about Reiner per se.

That said- well yes, I thought he was something, bizarre maybe! Of course, then, when he first posted, there was a long list of replies, (where I was silent!) which poked fun and refutation. ( I loved the squeaky pyrite one- that was funny!)

Lets not go on about what was simply intended as a humorous anecdote about ME, not him.
An old tune comes to mind, as Steve Winwood sang, ”…at the time I really felt that way, but that was then and now it’s today…”
(I changed my mind right? …and yes, I was laughing at myself as I was dipping my test specimens thinking, dang this is soo gross:)

As Rock noted (Correct Sir!) I really intended nothing but to add support to the utilization of the concept, wacky as it may sound… Don’t knock it till ya try it~ nuff said.

I do plan a written report for the Mindat community in support of the process where I will relate my findings with the local materials here. I’m honestly excited about getting that positive information out to people.
Of course, my support is just a short term data relay. Hopefully, replication of Reiner’s results will be across the board as to locales and duration… Time will tell:)

Sincerely,
~John O:)]]> John Oostenryk Mineral Cleaning and Preparation Tue, 23 Apr 2013 22:44:09 +0000 http://www.mindat.org/forum.php?read,19,149266,292074#msg-292074 http://www.mindat.org/forum.php?read,19,149266,292074#msg-292074
I'm better now. Thanks, John, for your remarks.

Maggie]]> Maggie Wilson Mineral Cleaning and Preparation Tue, 23 Apr 2013 21:59:19 +0000 http://www.mindat.org/forum.php?read,19,186968,292073#msg-292073 http://www.mindat.org/forum.php?read,19,186968,292073#msg-292073 No matter if he is starting to agree, he should apologize to Reiner for uncalled for offensive language.
John M.]]> John Montgomery Mineral Cleaning and Preparation Tue, 23 Apr 2013 21:48:36 +0000