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Techniques for CollectorsCleaning Fluorite
11th Sep 2004 22:50 UTCMG
11th Sep 2004 23:47 UTCLloyd L
If it's calcite, you'll need some sort of acid. Any acid will work, but you have to consider what it might do to the rest of the specimen and the risks involved to your well-being. Although organic acids such as acetic (vinegar) or citric should work eventually, inorganic acids are faster but present a greater health hazard. Commonest seems to be hydrochloric but many people favour phosphoric as this also has the beneficial side-effect of working on iron-stains too. Phosphoric acid is available in domestic rust-removers such as 'Jenolite'.
If too strong an acid is used, it can etch the fluorite.
Whatever method you use, please, please be very careful and if you are not used to, and have no proper facilities for, handling acids, get some expert assistance. You should also wear eye-protection if you go down the high-pressure gun route.
Hope this helps and you end up with a worthwhile, gemmy fluorite.
Lloyd
15th Sep 2004 02:56 UTCPeter Haas
A water gun is also not a good advice: fluorite is sensible to temperature and mechanical shocks, so the crystals may crack. Mud is more efficiently removed by soaking in water for a couple of days. It often consists of clay minerals or of ill-defined metal oxides/hydroxides. They can adsorb considerable amounts of water, which makes them swell. However, adsorption is a physical process and hence, rather slow, so it will take some time.
15th Sep 2004 19:26 UTCLloyd L
More science and less brute-force is always a good policy!
Lloyd
24th Sep 2004 08:26 UTCGunnar Färber
if you have only Flourite there, you can clean it very well in HF. But please HF works good but is also very dangerous.
Best Regards
Gunnar
24th Sep 2004 13:00 UTCPeterA
HF is not only dangerous, it's lethal in quite small amounts - even as a spill on bare skin (clothes soked in acid might even be worse). If skin are exposed and not washed/threated with special lotion (I think it's some kind of Ca-ionic lotion that neutralize the HF) after a short time after the exposure, the damages might cause a painful and slowly death!
I was presented an article when I started work in the laboratory at university about a tragical death caused by HF (I think it was about 1dl, on less than 150 square-centimeters of skin!). I never worked alone on the lab with HF after that! So nobody should even consider using HF outside a well secured labb with easy way to get treatment and help if the accident should happen!!! Even very smal exposures on skin should be treated by doctor.
Regards
PeterA
24th Sep 2004 13:24 UTCDanny
Danny.
24th Sep 2004 14:24 UTCDanny
24th Sep 2004 14:42 UTCAlfredo
30th Sep 2004 16:00 UTCChris van Laer
30th Sep 2004 16:22 UTCPeter Haas
Fluorite and HCl: Concentrated hydrochloric acid DOES attack fluorite to some extent (which is easily confirmed by the SiF4 test). The reaction is very slow and it is certainly not dissolved to any visible extent. Its brilliance may be lost, however, when it is exposed to the acid over a longer period of time.
Calcium gluconate and HF: An effective neutralization requires that the gluconate is applied immediately after the contact. This is a big problem, though, because HF is a rather weak acid. It does not etch the skin, it simply penetrates through it. There is big risk, that you don't notice anything, when you spill a small volume over your it. There are well documented examples of people who died within a few days after their hands or forearms had been contacted with a few milliliters of hydrofluoric acid for a short period of time.
Peter
1st Oct 2004 13:16 UTCAlfredo
This is true, but irrelevant to mineral cleaning, which is normally done with less than concentrated HCl. In fact, for many cleaning purposes, somewhat diluted HCl works better than conc. HCl.
1st Oct 2004 16:34 UTCPeter Haas
That's right. But - do we know whether people who are posting here, have ever handled chemicals before ? Could we preclude that they simply don't know that there are less and more appropriate concntrations ? They'll likely play around with the chemicals they use: for instance, they will find out that increasing the concentration will speed up the process. People tend to become impatient when they have to wait every time for something to happen, so this apparent advantage will overweigh any precaution - especially, if you don't know much about chemistry: you'll never be going to think about side effects - unwanted competing processes that become dominant at higher concentrations, or a complete change of the chemical and toxicological properties, for instance - and even less about the hazards. I still remember a cleaning advice proclaiming the use hot concentrated sulphuric acid, given by someone in this forum a couple of months ago ... and that's another important point: heating speeds up some chemical reactions, while others are almost not affected. When minerals are cleaned, desorption and displacement processes at phase boundarys do often play an important role. These are physical processes and they respond to different parameters than chemical reactions do. The speed of action of an oxalic acid solution on iron stains, for instance, is higher when the solution is permanently stirred (of course, this is a bit problematical, when the specimens are in it) than when it is heated.
Actually, I have to be aware of all that when I recommend a particular chemical. I also have to be aware that there is always the risk of a hazard, when people are not used to handle chemicals. Therefore, I have to recommend working conditions that are safe enough for not seriously hurting a person and not imparting any permanent damage in case of an accident. I certainly can't guarantee for that when the chemicals are used at different concentrations or in different conditions and, therefore, I have to tell people what may go wrong if they don't exactly follow the advice. I will be fully responsible if something happens what I didn't point out. The most common reason for misuse of chemicals is ignorance. Of course, It's their own decision to use chemicals, but I can't expect them to act responsible, when they have not been informed about any imagineable risk.
Many people think of chemists as eiher acting irresponsible, or grossly exaggerating. The latter might be the reason why many collectors are more easy to convince, when they're told that there is a risk of a permanent damage to their specimens ... There is, honestly, rarely any exaggeration, though.
Peter
1st Oct 2004 19:29 UTCBob Reed
45 years ago i worked in a steel works for a short time. My first job was to get a bucket of water and a carboy of Hydrofluoric Acid. I was then told to wash some skylight windows!! How times change. Needless to say the job was short lived.
Regards Bob
17th Jan 2005 14:11 UTClynna
I have mixture of 1g of fluorite+calcite with me.
Anyone here could recommend me any reliable test so that I would be able to know how much of fluorite presence in my 1g of mixture of fluorite and calcite?
One of the possible solution is to clean the mixture with hydrocloric acid but anyone here could give me a clue about the recommended concentration of hydrocloric acid that I should use for this?
Thanks in advane
lynna
17th Jan 2005 16:35 UTCDavid Von Bargen
If you have an X-ray diffraction machine, you could also do a powder diffraction (with appropriate standards for peak height of pure materials) pattern to determine percentages.
19th May 2006 13:45 UTCSergej Martynov
the material does not stand which chemicals, which chemicals doesn't the material bear?
If somebody could help me, that would be super
29th Jul 2006 08:38 UTCZbynek Burival Expert
18th Aug 2006 19:17 UTCAnonymous User
18th Aug 2006 20:20 UTCJ. R. Hodel Expert
One thing you should be aware of is that using liquids with your specimen that vary in temperature from that of the specimen may cause the fluorite crystals to spontaneously cleave off a large piece due to temperature differentials. I used plain old soap and water on a very nice fluorite from Illinois, and because the water was a little different temperature than the fluorite, a corner of the most prominent cube pooped off with a snapping sound.
So use water (or any fluid) that has had the opportunity to reach the temperature of the specimen rather than hot water (or even ice water) on a specimen at room temperature.
I recommend just a simple room-temp soapy water solution and a soft brush - you could let the specimen soak for a while, as someone above recommended - but don't introduce sudden temperature changes or the whole thing could come apart.
JR in WV
22nd Aug 2006 21:38 UTCAnonymous User
Thank you for the advice. I will try to develope my skills on a "less important" specimen. I'll let you know how things turn out! Appreciate the time and assistance.
Very Respectfully,
Steven
13th Jul 2010 20:45 UTCTori
13th Jul 2010 21:29 UTCReiner Mielke Expert
30th Oct 2010 02:44 UTCG. Matthews
31st Oct 2010 02:33 UTCRock Currier Expert
25th Nov 2010 07:40 UTCAnonymous User
You could clean you specimen using a sand blaster with Calcium Carbonate as an abrasive.This won't hurt the fluorite.
Hydrofluoric should be treated with Calcium glauconate after the acid has come in contact with the skin.A doctor should measure the surface attacked and use the appropriate amount of the compound.The purpose is to provide Calcium to the organism,not neutralize the acid.
The problem is that particles penetrate all tissues,react with the calcium and the result is hypocalciaemia.Calcium has an important physiological role for the heart function,muscles contraction and nerve system.
It is possible that the patient feels no pain due to the burn,because the calcium needed to release neurotransmitters has reacted with the acid.
The gel form is used for local treatment,but a patient with a large area exposed should need an injection.
It's certainly not an acid that can be used by an amateur and not even by a professional ,if the goal isn't really important.
The cleaning of a specimen isn't important enough to put you life in danger.Health is not only a right,but an obligation!
There are professional trimmers who will clean with Hydrofluoric and the price is low compared to the danger.
Don't play doctor of chemist!You need to be alive to enjoy your specimens!
Good health to all of you!
-Kostas.
16th Dec 2010 00:59 UTCJonathan Woolley
If I use a Super Iron Out solution will this hurt the fluorites? I hesitate to use any acid because of the carbonate matrix, and I suspect that the piece may have been cleaned with acid in the past because the fluorite is somewhat dull already.
16th Dec 2010 04:29 UTCRock Currier Expert
Super Iron Out will not harm any of the minerals on your specimen.
12th Mar 2011 22:55 UTCEvelyn Anderson
12th Mar 2011 23:51 UTCDon Saathoff Expert
19th Jan 2012 08:12 UTCfayyaz nazeer
i have tried fluorite crystals in HCL and HF but both types of acid effect the luster of fluorite very badly, so all user be very much careful in dealing with acids.
30th Sep 2012 22:49 UTCRock Hound in NJ
The second piece is new and comes in the usual green/blue/purple colors. It had been stored in a rock pile outside exposed to the elements. When I purchased it my hands got all muddy so I though a simple bath would do. I soaked it in water overnight and used a toothbrush. The bowl of water now stays clean but the rock still looks like it is covered in mud. Do I go to the drug store and ask for muratic acid? I appreciate any help anyone can give me.
Lastly mineral oil is mentioned above. Does using vegetable oil cause a problem?
1st Oct 2012 12:49 UTCRock Currier Expert
2nd Oct 2012 00:16 UTCDavid Zimmerman (2)
Rock is right though, a picture would really help out.
5th Feb 2016 05:59 UTCEdwina Lynn
Same with Labradorite?
Sea salt and water......?
5th Feb 2016 06:23 UTCAlfredo Petrov Manager
5th Feb 2016 06:29 UTCRanger Dave
8th Jul 2016 05:31 UTCSusan
4th Aug 2016 03:41 UTCJoyce
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