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Techniques for CollectorsCleaning Fluorite

15th Jul 2005 10:10 UTCDanilo

Hello,

tnks for the help.

I have nice Moroccan yellow fluorite which is partially covered with Iron Oxides. Are these best removed with a) Oxalic Acid or b) Phosphoric Acid. Better diluted in cold or warm water?

Should a yellow film remain on the specimen hoiw do I remove it?

I have a very beatiful large cabinet blue/green fluorite from Okorusu Mine in Namibia. 1/4 of the fluorite xls are covered by a patina of something (quartz?) that I am unable to remove. Does any of you hav had the some problem and any idea about how to clean it.

Many tnks

Danilo

16th Jul 2005 07:49 UTCEddie DeLuca

use Iron Out from wal-mart works great & fast after its cleaned rinse in water

Eddie

16th Jul 2005 07:55 UTCEddie DeLuca

to remove the quartz use Wink also from wal-mart soak in plastic bowl ( do not use glass ) when quartz is gone rinse in water with baking soda 3 to 1 mix for 1 hour then rinse i clear water

Eddie

16th Jul 2005 11:16 UTCJim

Somehow, I don't think Danilo is going to find a Wal-mart in Italy. From the MSDS (and the label) Super Iron Out is a rust stain remover that contains Sodium Metabisulfite and Sodium Hydrosulfite. Maybe there's a comparable product sold in .it

It does work well for removing iron oxides, and isn't nearly as harsh as oxalic acid. Of course you still need to follow all the usual precautions.

I've never tried oxalic, but I believe the trick is to remove the specimen to a fresh batch before the solution gets too yellow.

17th Jul 2005 02:45 UTCEddie DeLuca

Just have someone send it to you i send wal-mart stuff all over the world "Not a Problem"

Eddie

17th Jul 2005 16:52 UTCWilliam G. Lyon

Generally, exposure of fluorite to strong acids should be avoided because it will release HF gas and will etch the crystals. Oxalic acid will attack fluorite and will also produce an insoluble residue of calcium oxalates.

The ca. neutral solutions obtained from iron-out or similar concoctions containing Sodium Metabisulfite and Sodium Hydrosulfite seem the safest method for removing iron stains from fluorite.

Good luck with removing quartz from fluorite!

17th Jul 2005 19:39 UTCEddie DeLuca

The product Wink that is used in laundry to remove stanes & is found at Wal-Mart & other stores works very well to remove quartz, use out side with good ventalation, i own fluorite mines in New Mexico & this is what i use.

Eddie

18th Jul 2005 10:10 UTCDanilo

Hi everybody and tnks for the answers.

I will have a friend of mine going to a Wal-Mart and buy the stuff for me.

The Iron Out it is the Super Iron Out product from Iron Out Inc, correct?

I have surfed the web site but cannot find Wink. Eddie, can you please tell me who is the manufacturer of this product and what chemical agents does it cointain.

Tnks

Danilo

18th Jul 2005 11:04 UTCJim

Yes, Super Iron Out is what you want.

Just FYI, I have had one or 2 bad experiences with SIO. In one case it stained clevelandite feldspar greenish (where other clevelandite from the same mine came through fine). Another case with altered mica (vermiculite?) embedded in smoky quartz xls turned a very ugly green (knew about this beforehand but just had to see it for myself).

You should be fine though, it's worked well for me plenty of times. Do test on a junk piece if you have one available, just to be sure.

18th Jul 2005 21:00 UTCEddie DeLuca

http://www.whink.com/rust_stain_remover.htm

Danilo go to this link

i spelled it wrong Whink

Eddie

18th Jul 2005 21:04 UTCEddie DeLuca

Danilo

on the last note i forgot to tell you it containes HydroFluoric Acid, this Removes the quartz.

Eddie

18th Jul 2005 23:16 UTCPete Nanacrrow

and fingernails, bone, lung tissue etc.

Pete N.

19th Jul 2005 04:50 UTCEddie DeLuca

Pete N.

Whink is not that bad it is watered down Wal-Mart sells it to remove rust from clothes

Eddie

19th Jul 2005 08:36 UTCDanilo

Eddie,

thanks for the link.

For how long do you let the fluorites into Whink to remove the quartz patina? I suspect if do it for too much time you get a damaged/dull fluorite too.

Danilo

19th Jul 2005 10:40 UTCPete Nanacrrow

Eddie,

If you are sure that there IS hydrofluoric rather than hydrochloric acid in the Whink product, and it's being marketed at a dilute enough concentration to be legally sold to the public for domestic use as harmless to human tissue, I would be surprised if it is effective at dissolving quartz. Products containing dilute HCl can sometimes help to remove crusts of quartz by attacking a thin of layer of soluble mineral between the quartz and a substrate not affected by HCl . When I say thin, I am including invisibly thin layers. I have examined mineral samples by scanning electron microscope as part of mineral processing trials, to evaluate etching/solution/grain separation effects and rates, and have found cases where acid has seeped along veins and cracks a few microns wide, to remove crusts of, or break up granular masses of minerals not actually soluble in that acid.

Hydrofluoric acid is a seriously dangerous substance, both insidiously corrosive and very toxic by vapour inhalation. I have no qualms about using HCl, H2SO4, HNO3, glacial acetic etc. up to very high concentrations with appropriate ventilation, eye protection etc, but the concentrations of HF neccessary to dissolve quartz and silicate minerals for analysis in laboratories are so hazardous that dedicated areas with special trained first aid attendants and facilities, spillage containment kits, and laboratory evacuation procedures in the event of a major spillage have to be set up before it's use is authorised.

Pete N.

19th Jul 2005 11:33 UTCEddie DeLuca

Pete N.

works perfect, it takes a little time but it works very well,

Danilo

just keep cheking on it when its gone take it out, some times it takes weeks if the quarts is thick & you may have to add more to keep it strong.

Eddie

19th Jul 2005 14:43 UTCPeter C

Apparently Whink does contain HF. See the Material Safety Data Sheet: www.baneclene.com/msds/whink.pdf.

20th Jul 2005 01:15 UTCEddie DeLuca

Danilo

many people use Whink to remove the Quartz frost off of the Smokey Quarts from Smoky the bear claim in New Mexico & off the Pine canyon fluorite from New Mexico

its slower but safer than full strength HF acid

some times a month or more

But it does the job

Eddie

24th Jul 2005 09:28 UTCBernhard

Hi Eddie,

would it be possible to ship these two chemicals from Wal-mart, to austria, we don´t have anything like theat here and what would this cost?

Thanks Bernhard

7th Nov 2005 18:57 UTCdanilo

Hi Eddie,

thank you. I got the Super Iron Out and it worked very well.

Eventually the fluorite remained a bit dull.

Anything I can do to make it shine?

Anyhow, it was a good advice. tnks

27th Nov 2005 00:03 UTCGrandMaster Eddie DeLuca

Spray it with Food Grade Silicone, this works well for me

Eddie

3rd Dec 2005 06:03 UTCJesse Fisher

Based on a couple years experience cleaning not a small amount of fluorite from a little muddy hole in Northern England, I can say a couple things about the process. First, NEVER use oxalic acid on fluorite - it will deluster it almost without fail. hydrochloric (muriatic) acid can sometimes do the same thing. The best general purpose chemical to remove iron stain is sodiun dithionate, which is the ingredient of interest in Wall Mart's Iron Out. If your fluorites are heavily stained, it is best to add a bit of citric acid to the dithionate solution to keep the dissolved iron in solution, in case it becomes saturated. If an acid is needed, stick to phosphoric.

Second, if, after cleaning, your fluorite is still dull, it is likely because the surface of the crystals is etched or pitted. Silicon oil will help the appearance a bit by filling in fractures, but short of polishing the crystal faces, your pertty much stuck with what you have.

Lastly, I strongly agree with Pete N's opinion of HF. It is extremely nasty stuff, even dilute, and should never be used by anyone who doesn't have considerable laboratory experience, and access to the proper safety equipment. If you must go down the path of available fluorine radicals, ammonium bifluoride is a much safer choice. It is still a strong, corrosive chemical and should be handled with proper safety precautions.

Jesse

1st Apr 2006 20:45 UTCKimball

Hi. I have been reading this log, and had some other questions. I will try the SIO, and Whink, but I have a piece of the DeAn Fluorite from China. There are no rust stains and it is on the white matrix of very delicate needle crystals. The piece remains totally chalky on the crystal faces when it dries, no matter what I do to it. Wet, it looks wonderful. Also the white matrix is more of a dull tan. What can I soak this in that will not pit it, can remove the chalky covering, and will clean the discoloration off the white matrix? One of the 2 solutions above? I have several other pieces that are prisitine, so I assume it is possible. (every piece is different though). The chinese seller described the cleaning process with H2F2, but I am not going anywhere near that stuff ;) Also what is the white matrix mineral?

Thanks so much.

Cheers.

kimball

14th Apr 2006 01:34 UTCJon de K

Hello,

I have exactly the same problem with my fluorite specimens as Kimball. Please let me know if you know of an adequate solution. I feel the same way regarding strong corrosives... I'd rather not deal with them at all. In the past, I have used various acids to clean a pool I once owned. I didn't like that much at all. I did notice how quickly it etched concrete, etc. and I'd prefer not to think of what it would do to skin.

Thanks!

Jon

24th Apr 2006 22:42 UTCColin Robinson

After forty years of cleaning north British fluorites I can only agree with Jesse. Sodium dithionite solution is by far the best method for removing rust staining. Oxalic acid works great on quartz but if you have fluorite and quartz in association then stick to dithionite. I use dilute hydrochloric acid to get rid of calcite coatings and if you dilute it enough it seems to have no bad effects on the fluorite. DIY stores sell brick and patio cleaner which has dilute HCl and a detergent. I dilute this much further with warm water and it still seems to work faster than Phosphoric acid.

In the later years of working at Frazers Hush mine a lot of fluorite specimens came out coated in a black, partly oxidised iron mineral, probably a sulphide. This we removed with strong hydrogen peroxide. The reaction was exothermic and produced a great deal of heat, causing the solution to boil, and the only way to slow it down was to remove the specimens (with wooden laundry tongs, not bare hands!). Unfortunately the fluorites came out rather dull and etched but a light application of oil brought them back again. Here we get into the question of presentation of specimens. Do we want them completely natural or are we going for the most aesthetic? A dealer friend brought the lustre back by shot blasting with tiny plastic balls but most of us don't have access to such equipment.

I know its been said before but if you are going to use chemical cleaners please work in the open air and always with appropriate safety equipment. In a lab with pure chemicals you can be pretty sure what's going to happen but lumps of rock can contain almost anything and you've no idea what reactions are going to take place.

25th Apr 2006 14:27 UTCAndrew G. Christy Manager

just a couple of notes about sodium dithionITE (not dithionATE, which is different and does not work!).

1. The active compound is also known as sodium 'hydrosulfite'. Formula is Na2S2O4 (not Na2S2O6, which is the unreactive -ATE).

2. Acids will decompose it. You want to use this stuff in neutral or slightly alkaline solution.

3. It acts by reducing insoluble Fe3+ to soluble Fe2+ (and insoluble black Mn4+ to soluble, pale-coloured Mn2+). Citrate added to the solution complexes these ions and keeps them stable in solution - otherwise, they can reoxidise and clunk out again all over your rock(s). If you use citrate as citric acid (cooking grade is fine), you should add plenty of sodium bicarbonate (bit at a time since it froths up like mad) until the fizzing slows down. Do not add the relatively expensive and reactive dithionite until after you have achieved this state.

4. Because this works in neutral to weakly alkaline solution, you can use it to de-rust even carbonate minerals without them getting badly etched.

5. The first thing that dithionites react with is the dissolved oxygen in any water that you mix them with. You should keep your soaking rocks in an air-tight container to prevent more oxygen getting in and zapping your active ingredient.

26th Apr 2006 19:00 UTCJesse Fisher Expert

Kimball;

If your fluorite was cleaned using hydrofluoric acid, the white chalky coating may be a residual, amorphous silica. Without resorting to another application of HF, the best way to remove it would be mechanically, using either a high pressure water gun or an air abrassive unit with a soft powder such as plastic.

Jon;

The pool chemical you have is hydrochloric acid (HCL, also called muriatic acid). It is a strong acid, and thus dangerous when concentrated. It also fumes quite a bit so should always be used with good ventilation. In a dilute solution, it is useful for removing unwanted calcite or iron staining from acid-resistant minerals such as quartz, tourmaline, micas, and feldspars. Best keep it away from your fluorite, however.

20th May 2007 16:05 UTCGrace Oranchuk

To Whom it May Concern, I have just purchased Sodium Hydrosulfite, at a place that sells bottled water the lady there suggested it can be used to clean sinks, toliets, tubs, washing machines, dishwashers. My question is can it be used to clean a water distiller which is used to distill water, and if it can I believe that the container shpuld be well rinsed with clean water and maybe even the first time of use after cleaning the distiller it should be thrown out. The other thing I kinda found the smell offensive and will likely need a mask to use the product as have a Sulfer allergy. Did use the product to remove a rust residue on Stainless steel, but need to redo it as did not quite clean it up. Could you please respond to my email if you have any answers Thank-You

Grace

20th May 2007 16:29 UTCDavid Von Bargen Manager

Well, it depends upon what you are trying to clean out of the distillation unit. If you have a lot of iron precipitating in it, it is an effective way of removing it. If it is a calcite scale problem (hard water), then a weak acid would be what you want to use (either get the manufacturer's recommendation or use vinegar).

http://www.extension.umn.edu/distribution/naturalresources/DD5943.html

20th May 2007 19:42 UTCMatteo Chinellato Expert

I am under texted ossalic acid on a piece of fluorite, tomorrow i seen the result after 2 days

29th May 2007 08:37 UTCRobert W. E. Neilson

Great technical advice from Jesse and Colin...2 men who know more about cleaning flourite than the rest of us put together and exactly why this site is so useful. Not that I even need to clean any at the moment but the thread was very interesting and now I am a wiser man!

8th Jun 2007 11:14 UTCRock Currier Expert

Danilo

If your fluorite specimen from Okorusu has a coating of fairly well crystallized quartz you are not going to be able to clean it with any reagent they sell commercially over a retail counter. You will have to resort to using hydrofluoric acid to remove thicker crusts. This I would advise strongly against. The cost of setting up to use this chemical safely would not be worthwhile. If you have a contract with the mine and need to clean quantities of mine run Okorushu fluorite it might be profitable to set up a hydrofluoric cleaning operation, but you had better be sure you really know what you are doing. If you have one specimen to clean and it is coated with a thin film of silica or crust of poorly crystallized quartz, by all means try to use a commercial product like Whink over a period of some days or weeks and it might remove it. I think the active ingredient in such reagents is ammonium bi fluoride which will hydrolyze in water releasing the fluoride ion which will chew away a little on the silica/quartz, perhaps enough to clean your specimen. I have cleaned some Okorushu fluorite and found that if the specimens were fairly heavily coated, the specimens of fluorite recovered after the removal of the silica/quartz were rarely ever as nice as the ones that had little or no coating.

The DiAn fluorite from China comes from a big open pit mine and almost all of it is heavily coated with not just a thin crust, but thick crusts of quartz. When I was there I was offered mine run material for less than $500 a ton. The thought of breathing HF fumes for a few weeks combined with the specter of hazmat teams descending in space suits was sufficient to stay my hand from my wallet. Our brothers in China, ever aware and anxious to make a profit by selling specimens to their western cousins, are far less squeamish about the very liberal, even excessive, use of hydrofluoric acid to remove what ever quartz is necessary to make saleable mineral specimens. Hydrofluoric acid by the drum is cheap in China and if the resulting specimens are not very shiny, the oil needed to make the specimens more presentable is also inexpensive. The only unetched specimens I have seen from this mine in the west would more properly be called quartz specimens which are of much more interest to interior decorators than collectors. We bought abut a ton of these. Most of the specimens offered for sale to collectors in the west have all been etched within an inch of their lives and it is doubtful that any further cleaning or etching with anything will do them any good.

Rock

28th Jul 2007 23:38 UTCRickS

Eddie, thanks for the Whink tip. I'm ready to clean a batch of fluorite. How much of this product to you use in a 5 gallon bucket?

Rick

5th Oct 2007 19:12 UTCStephen C. Blyskal Expert

Hi, I have been offered a lot of mine run fluorite from an unknown location in Er Rachidia Prov., Morocco. I have attached several pics of the ones I was sent. A lot of of the fluorite looks like it has an iron stain of varying degrees of thickness on it. I would like any advice from people on how difficult it might be to clean this stuff. I have read the thread and see that Super Iron OUt or Whink might do the job. Any comments will be appreciated. The specimens would average $6 each shipped to the USA.

5th Dec 2007 20:25 UTCDoug Coulter

I have cleaned a lot of minerals since I am a part time mineral dealer. Usually Oxalic or a water gun does the trick. I recently acquired a piece of Okorusu fluorite during a trip to the mine. The mine geologist suggested hydrofluoric acid, but i am smarter than to use this stuff.

I cleaned the calcite coating with HCL, but now I am left with an iron coating. I am trying IronOut but do not know the concentration amount or how long it takes, Should the solution be heated? I use an old croc pot for this purpose. Anyone have advice on IronOut? Does it take a long time?

6th Dec 2007 03:22 UTCJesse Fisher Expert

The active ingredient in Super Iron Out is sodium dithionite. It works well to remove iron stains without acidity. I would make a solution of around 5-10 grams per liter of water. If the iron stain is particularly heavy I would add some citric acid to help keep the solution from becoming saturated. If this happens, the fe-ox will repercipitate back on your minerals with less than pleasant results. It will work well at room temperature, but gentle heating maybe 40-50 C will help accelerate it. Unheated, treatment should take no longer than 8 hours.

And let me repeat myself from other threads. NEVER use oxalic acid on fluorite unless you want a matte, frosted luster.

16th Feb 2008 05:34 UTCKevin Xu

I cleaned more then 100 specimens of Yaogangxian fluorites-conclusion is hydrofluoric acid is the best way for fluorite,otherwise you're really gonna regret if try fluorite with HCL or oxalic acid, while use hyfrofluoric acid, just dilute it with water about 1 hydrofluoric acid to 15-20 water,it merely takes a few mins,BUT the color of fluorite will get a little bit light.

kevin

16th Feb 2008 14:39 UTCDavid Von Bargen Manager

Hydrofluoric acid can be extremely nasty to people and should only be used by those that know what they are doing and take the appropriate safety measures (which are difficult to impossible to do in a home setting).

5th Mar 2008 20:22 UTCDoug C

I have just purchased some ammonium biflouride to clean some heavily iron stained Okorusu fluorite and some Erongo smokey quartz and schorl clusters. What concentration should I use(10%, 20%, etc.). How often can a batch be reused? Once finished, how is it naturalized so it can be disposed of?

Cheers

5th Mar 2008 22:16 UTCJesse Fisher Expert

I would not recommend ammonium bifluoride for removing iron stain. It, like HF, will release fluorine radicals in solution and is primarily of use in attacking silicates. It will loosen any clay, feldspar or quartz encrustations from fluorite, but will attack quartz and possibly schorl, albeit more slowly than HF.

6th Mar 2008 16:23 UTCDoug C

Well that leaves me with few options for cleaning the fluorite. I have a large cluster of the new "dice" fluorite that I got at the mine. The metalalurgist said use HF but I will not. John Seibel saw it at Tucson and said he thought only HF would get the heavy iron stain off. But he did say to try the ammonium bifluorite.

I have tried Iron Out to no avail, but then again I do not know how strong to make the solution or how long to leave it in. The specimen could be museum grade if cleaned but virtually worthless stained.

24th Jun 2008 05:12 UTCAnonymous User

hi,

i have similar problems and have read some different methods.

i have some huge fluorite chunks that had some yellow stains from muriatic acid. i was able to get alot off with just plain water, but would like clean thenm better. should i use iron-out or should i clean them again with muriatic acid?

please explain procedures for cleaning with muriatic and for cleaning with iron out? cleaning times? dilutions? rinsing?

also, silicon is recommended for final polishing. what kind/brand of silicon?

thanks for answering my noob questions

24th Jun 2008 11:26 UTCJon Mommers

In a past life, I as part of my role, I was responsible for OH&S in a forging company that produced titanium compression blades for jet engines in the US and UK. The company had seven baths of concentrated HF, each containing approximately 20 thousand litres used to remove silica; which was used as flux/lubricant during the forging process. During the seven years I was in this role, we had one HF burn, a small splash on a hand, the operator immediately irrigated the effected area and the recommended creams were applied. All appeared well, until 2

weeks later when the HF burnt area on the hand turned black...... HF burns from the inside out. Do not be fouled by false bravado or hype ( it can never happen to me; aka I am 18 and indestructible), HF can very quickly ruin your life. Its use and the use of other fluorine products, is not worth the pain and suffering it can bring.

Listen to what experts like Rock and Jesse have to say about cleaning Quartz, Fluorite etc. They have gained their knowledge and wisdom through experience and study and years of experience.

Save yourself and your family the grief and if in doubt do with out. No specimen is worth your health.

Peroxide is nasty, HF is a killer

Jon

25th Jun 2008 02:14 UTCAnonymous User

yea, i want to avoid the chemicals.

but still my questions unanswered.

can someone at least answer the "safe" question... what kind/brand silicon oil is used for touch up polishing of fluorite?

thanks

23rd Oct 2008 02:39 UTCsusan thompson

where would you find food grade silicone

also, I just visited a fluorite mine and can see galena cubes as well as purple fluorite trying to peek out of the base fluorite.

How can I make the good minerals"show their stuff" without damaging them.

I am a total rookie, so be kind and specific.

susan

23rd Oct 2008 18:27 UTCAnonymous User

Hi all!

Just to remind the folks about Hydrofluoric- I met a couple of weeks ago a patient/friend of mine who had an incident with HF and all the tissue of his finger was removed showing the bone. After a three months therapy hasn't fully recovered yet.Additionally, he realizes that he has paid more for medical cares and supplies than he would have paid to a specialist to do the job.

DO NOT USE THE ACID!

-Kostas.

23rd Jun 2009 00:40 UTCGrand Master Eddie DeLuca

danilo

Yes, use food grade silacone spray,this works very well.

Eddie

23rd Jun 2009 00:42 UTCGrand Master Eddie DeLuca

danilo

Let me know how you think it worked for you ok,

Eddie

16th Aug 2009 01:46 UTCXcellentform

I just bought a Rogerly Mine fluorite that has a medium thick coating of a white mineral on the cubes. I was hoping it was a carbonate and tested a little muriatic on a bad spot, but that did not do the trick. I am now thinking it might be a silicate. Does anyone know the mystery white mineral from this historic local and what it takes to get it off? I see some Brits on here! Thanks in advance.

16th Aug 2009 06:17 UTCJolyon Ralph Founder

Quartz?

Only thing that will shift that off of fluorite is Hydrofluoric acid (HF) and you really don't want to be using that. Nasty stuff.

Jolyon

16th Aug 2009 08:45 UTCJesse Fisher Expert

We have occasionally found quartz-coated fluorite in some parts of the mine. It is easy to tell it from calcite/aragonite with a stereoscope of hand lens. We have tried removing the quartz coating from a few specimens but the underlying quartz is always pitted and rather unattractive. You might just want to leave it alone.

16th Aug 2009 22:23 UTCXcellentform

Thanks Jolyon and Jesse for the quick responces. Let's assume it's quartz and let's say it is 1 mm thick. Is this the type that you tested on Jesse or was the quartz thicker? I'd say I have a 75% coverage of quartz over the fluorite. It is a large plate, but I only paid $40 for, so I'm not out a lot of money if the piece is ruined. It also looks good the way it is too though. I'm tempted to try the Whink product from above. Any other thoughts before I run to Wal-Mart!! Thanks in advance!

6th Jun 2011 00:16 UTCRandy

I see this was a long time ago but maybe some one is still reading this. What Whink product are you using for quartz? Whink has all kinds of products that clean stains.

6th Jun 2011 07:32 UTCJesse Fisher Expert

The ingredient of interest in "Super Iron Out" is sodium dithionite, which is very good at removing iron stain from fluorite. I know that this can be obtained in at least some European countries as I have it for sale at the Ste. Marie show. I recall there have been other threads discussing the details of its use here on Mindat.

Do not ever use oxalic acid on fluorite unless you want your fluorite to be seriously delustered.

13th Oct 2012 21:39 UTCM.ibrahim Rehman

Hi . I have a good parcels of flourite minerals but its have yellow iron st. How to wash and clean this piece this flourite from Pakistan origin . Please let me know in details by step and duration of each step (time) thanks

13th Oct 2012 22:27 UTCRock Currier Expert

M.ibrahim Rehman,

Could we see a picture of some of the specimens you want to clean?

10th Mar 2013 11:17 UTCMaureen H.

Since you seem to be the most knowledgeable person on the subject of florite, maybe you can tell me why for days after I touch a piece everything tastes salty? My lips are salty day and night. If I hadn't washed my hands there seems to be no end to it. It's on everything. I only just got my fist florite and noticed this. I spent the afternoon cleaning everything I touch a lot and still can't get rid of it. HELP! Is this normal? I haven't come across this affect on any site yet about this mineral.

10th Mar 2013 17:29 UTCDavid Zimmerman (2)

Welcome to Mindat Maureen! :)-D

I can't say that I've ever heard of fluorite being salty....but it could depend on the environment on where it was collected. Fluorite is a safe mineral and you can certainly wash it without damage. BUT, there is a VERY good possibility that you have a mislabeled specimen and you are indeed holding Halite (salt) crystals instead of fluorite. I could see where they could be confused. A simple scratch test should be able to solve this, even though the hardness's are similar. If it is Halite, which I it very well might be, then don't wash it as you will dissolve it away.

Maybe if you supplied us with the location information and a great, clear, photo, we might be able to identify it that way. I would assume that if it were Halite, that the edges would be somewhat rounded and that a fluorite crystal would be nice and sharp. Also, if it were purple than I would tend to think fluorite and if it were clear, I would lean more towards Halite, but color would not be the definitive tool for identification with these two.

12th Mar 2013 09:13 UTCRock Currier Expert

It is not altogether clear from your picture that the offending material coating the fluorite crystals is "iron staining". How many specimens have you been offered? It is one thing to clean a few specimens depending on what is being cleaned off, but another matter if you have to clean hundreds or thousands. Before you cut your final deal I would want to get a few samples and find out exactly what is going to be involved. The first thing to do would be to find out what the coating is if possible and experiment and see if a standard reagent like iron out will clean them sufficiently.

18th May 2013 20:47 UTCToniH

Long after this discussion, I know, but I've had luck restoring shine by soaking certain minerals in mineral oil. My hubby thinks that's cheating, but I don't think it is cheating any more than removing unsightly minerals, rust, etc. that take away from the specimen. If it is for a competition, remember to check the rules!

18th May 2013 21:58 UTCRock Currier Expert

ToniH

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.

27th Jun 2013 04:16 UTCSimon Baxter

:-DWOW! and here I was worried about using a little vinegar on my calcite....

16th Jul 2013 00:22 UTCBrian Paterson

Considerable activity in this stream - and for many years!

Have to love Mindat for carrying it for so long.

Here's my two cents, now at a penny and a half...

First of all, I cheat - I've been a chemist in a former life.

HF is nasty, however the thought it burns from the inside out is incorrect, as much as a microwave cooks from the inside out. It doesn't. Either one. The problem is water as a neutralizer for HF. Water has a PH of around 7, or neutral, neither an acid nor a base and as such can only dilute the reagent rather than destroy it. If you wish to be safe around HF (whatever that means) have some baking soda handy to put on places that the HF shouldn't go. Like skin. Mix the baking soda with water to form a ready-to-apply solution and sloooowly pour the solution over the affected area. You certainly don't want to spread the acid further. Slow and steady, please.

H Cl (Hydrochloric acid) - same idea.

Oxalic acid is an acid, too.

Suggestion - use a bucket to contain the baking soda/water solution. About 3/4 full so that the whole arm/hand/foot can get into the act. Pour it over your head if necessary or chest, etc.

However, moving to the basic side of life, if you are using bases to clean minerals, then you'll want to have an acid handy to neutralize the reagent. Vinegar (5%) makes a fine solution to this problem. (Sorry..."5% solution" ? Never mind.) Have a small bottle handy to slooowly pour over the affected area again. Most don't use bases to clean minerals, but they do work.

OK, my bench looks like a WW1 minefield - pits everywhere from acids and bases. I used to neutralize later, but the acids and bases got into the wood under the formica (or whatever) top. I now have paper towels in solution to place, gently, over the spill. My bench is 1/4" plastic sheet with raised edges so that spills don't hit the floor. Use plastic cement to "weld" strips in place.

Fume hoods - here's a thought for those in the North. Get an oven hood (I found one that was plastic) and mount it directly over your area of operation. Take the grease screen and original fan and pitch them both. Using a side fan (takes air from the side and injects it into the air stream, causing the entire air mass to move - check your furnace blower fan for the right idea) create a "Y" tube facing the bottom of the "Y" towards the outside of the dwelling. One arm of the top of the "Y" is the hood, the other the blower. Use plastic tube to run outside to plastic vents. NO METAL. I use this method to perform low-yield testing of minerals before I do larger runs, which are *always* outside. Saves me from freezing my back-side while I get the method correct. Again - NO METAL in the main exhaust air flow, but the blower fan can certainly be metal as it is not in the main flow. Did I stress "low yield" enough?

I have to look at the Iron Out again. Something in the back of my mind about neutralizing it.

Here's the thing - don't hurry. Don't make more of a problem fixing it than you've already created. Yes, by all means, get the neutralizer to the problem as fast as is practical, but don't spread the problem to adjoining areas.

I also oxy/acetylene weld, so my face mask, which is normally clear as glass unless I'm burning, makes a fine face mask for chemical work. About $30 well spent dollars.

I have two questions on Fluorite, but another time.

Any return questions on the above?

Cheers,

Brian

16th Jul 2013 00:51 UTCBrian Paterson

About the Sodium Dithionite:

Sodium dithionite is stable when dry, but is slowly oxidized by air when in solution. Thus solutions of sodium dithionite cannot be stored for a long period of time.

Worse, powdered anhydrous sodium dithionite with a small amount of water may ignite in air by the heat of decomposition. Keep this puppy tightly sealed, dry and remove as much space from the package as possible when sealing. Remember the fume hood idea?

An aqueous solution of sodium dithionite is acidic! Use proper precautions if you're using the pure chemical.

In presence of oxygen, it decomposes to Sodium Bisulfate and Sodium Bisulfite. Sodium bisulfate and sodium bisulfite decrease the pH and therefore accelerate the reaction. Sulfur dioxide is formed under strongly acidic conditions. This, in the presence of water, forms Sulfuric Acid, Sulfurous Acid and Hydrogen Sulfide. H2S, Hydrogen Sulfide, kills. Quickly! Don't put another strong acid in with this acid!

Iron Out contains buffers to stop some of these reactions from occurring too quickly.

Pure reagents are great and, often, are cheaper and work faster. They can also kill faster.

Curiously, I have more respect for Sodium dithionite (also known as sodium hydrosulfite) than most other chemicals.

Brian

6th Dec 2014 05:34 UTCKeith Hilbert

This is a piece of botryoidal fluorite from Colorado. The white film is a combination if Chalcedony and Calcium Carbonate. We have tried Sulfuric acid, Hydrochloric acid(35.8% diluted 10 to 1), Sulfamic acid,I have a product by Whink. Its a rust stain remover which is 1.5 to 3.5% hydrofluoric acid, which Ill try next. HF is the only chemical, besides cyanide, that etches away quartz

. Has anyone tried phosphoric_or nitric acid on Quartz. I dilnt like the idea of using HF but it gets old spending so much time w picks and fies.

6th Dec 2014 06:18 UTCDoug Daniels

If you are trying to remove the quartz, neither phosphoric acid nor nitric acid will remove it. Hydrofluoric acid will, but there are to many dangers associated with it to bother with it, unless you have all the proper precautions (there are other threads addressing these).

6th Dec 2014 17:15 UTCRock Currier Expert

Why do you say the crust has calcite in it. After a dip in hydrochloric acid, any calcite would be etched away. Sodium and Potassium hydroxide will also dissolve quartz, but it can take some time and I don't know what it would do to the fluorite. I think that Whink or the dreaded HF are the only practical options left open for you to improve the specimens.

24th Feb 2016 14:33 UTCKen Lowe

Hello,

I'm writing on behalf of my partner, who is a jeweller, designer, maker.

She has been troubled for over six months now with a particular ring that she has designed utilising fluorite crystals.

The rings design is a 'U' shape with two rods passing through it a third of the way down. The Fluorite is 'set' on top of two silver rods and between the two upper sides of the 'U'. It is fixed in place with Araldite (although Super Glue had been tried) where the crystal touches the metal.

Her problem is not only the glue not retaining the crystal but also the cleaning off of the Araldite from the Fluorite. Any suggestions that might help to restore the dozen or so crystals back to their original condition?

Thank you, Ken.

24th Mar 2016 18:55 UTCReiner Mielke Expert

I guess there is a concentration level below which HF is relatively harmless just like acetic acid.

25th Mar 2016 05:50 UTCVolkmar Stingl

Reiner Mielke Wrote:

-------------------------------------------------------

> I guess there is a concentration level below

> which HF is relatively harmless just like acetic

> acid.

HF is NEVER harmless! It is not only strongly etching, it will also diffuse through the skin and affect the bones. Even low concentration HF should not be underestimated!

22nd Oct 2016 16:28 UTCLaurence M. Nuelle

From all the above discussions, I cannot tell if phosphoric acid is used to get rid of calcite or rust or both? Also, no one mentions how much it should be diluted, if any. I presume it does need to be diluted if you have the concentrated material (85% if I remember right). I just bought a large lot of Illinois fluorite, some need to be cleaned to remove rust (Iron Out is what I ususally use) and some needs to be cleaned to get rid of calcite. I tried very dilute muriatic acid for the calcite, but even a very dilute solution seems to etch the fluourite surface. I purchased a quart of Rust Cutter from Tractor Supply Company; it is phosphoric acid-based and seems to work well on getting rid of the rust on the fluorite, better than Iron Out.. But, it is expensive being just over $20 for the quart-size bottle. So, getting back to concentrated phosphoric acid -- how much should it be diluted and will it remove rust, calcite, or both?

Larry Nuelle,

Fall Creek Rock Shop

22nd Oct 2016 16:48 UTCDavid Von Bargen Manager

Did you check out the label for Rust Cutter. They will usually have an ingredient list (and maybe %s).

Using phosphoric acid to remove calcite is a bit problematic. The chemistry would suggest that you would end up with calcium and phosphate ions in solution (combination will be something like apatite - which isn't going to be particularly soluble)

22nd Oct 2016 19:21 UTCLaurence M. Nuelle

Good point; I hadn't thought about forming apatite using phosphoric acid. The label on Rust Kutter says it is confidential, but I do know it is phosphoric acid in it and it takes rust off quite a bit faster than Iron Out (at least for the few I have done so far) and does not change the luster of the fluorite. The only problem is that it comes in a spray bottle and is expensive. I do have a gallon of concentrated phosphoric acid -- do you know what the dilution factor should be for rust removal?

22nd Oct 2016 19:43 UTCWayne Corwin

Laurence

Are you using Iron Out,,,, or Super Iron Out ?

Makes a diffrence.

Also,,, Look at the MSDS safety sheet site for Rust Kutter ingredients,, it's not "confidential" there ;-)

23rd Oct 2016 14:37 UTCLaurence M. Nuelle

Wayne

Super Iron Out is what I use. Part of my problem is that I make sure that the cleaning solution is not very warm or cold because many of the fluorite crystals are very clear and I want to avoid internal cleavages from dumping them into a too warm or too cold a solution. Nothing worse than hearing a crystal "tinkle" whlen placed in a solution of too great a temperature change. I think that Super Iron Out works best when warm as when I clean chalcopyrite.

I will look at the MSDS sheet to see what it says. I am going to try a dilute phosphoric acid solution today or tomorrow; probably I will use 80% water and 20% acid. I'll see if that removes the rust. And, we should always remind people who might be reading these posts to "always add acid" as adding water to certain types of acid can cause a violent reaction.

Larry

23rd Oct 2016 15:25 UTCLaurence M. Nuelle

Wayne:

Here is composition of Rust Cutter. It has about 45% to 55%% phosphoric acid, a touch of citric acid (3% to 5%) and a couple of other components. I guess why it seems to work well is because of the phosphoric acid with the citric acid as recommended by previous posts. I am not sure what the other two components do. Note that the percents is % by weight. So, using this as a guideline, I probably should try a 50% solution of phosphoric acid and a bit of food grade citric acid which I also have on hand.

COMPONENTS CAS# % BY WT OSHA,TWA(ppm) NIOSHA STEL(ppm)

Phosphoric Acid 75% 7664-38-2 45-55 1MG/M3 3MG/M3

2-Butoxyethanol 99% 111-76-2 5-9 50/skin 50

NP-9.5 9016-45-9 2-4 ---- ---

Citric Acid 77-92-9 3-5

Larry

24th Oct 2016 13:16 UTCKeith A. Peregrine

Iron Out did the trick on a fluorite which had some iron staining. Let it set in an Iron Out solution for about an hour at somewhere between 65 and 70 degrees F. After a light brushing with a soft brush, it cleaned up wonderfully without harming the luster.

Tried it on another fluorite having a barite underside. The barite was covered with a thick iron coating. Soaking for an hour as the previous piece, most of the iron staining was removed without damaging the fluorite or barite. Unfortunately, with all the nooks and crannies in the barite, it was not possible to remove all the iron staining. Still, it looks much better than before. What's nice, is that under sw uv light, the barite fluoresces much better now.

Thanks for the advice, everyone!

25th Oct 2016 01:47 UTCLaurence M. Nuelle

I think part of the problem with my fluorite from Hardin County, Illinois is that the rust is not a simple iron sulfide oxidation as some specimens with rust do not have a trace of iron sulfide. What the miners here call rust is not always what most mineral collectors think of rust. I am not sure what the material is: it is kind of a dark gray coating of some sort. Super Iron Out is very slow on it (often over a day). The phosphoric acid-based liquid is faster in removing whatever the material may be. On the other hand, if a specimen has oxidized pyrite, marcasite, or chalcopyrite, the Super Iron Out cleans up the sulfides almost immediately. So, I am thinking that there are two types of "rust" to remove on these specimens. With all the ideas and suggestions from the above posts, I believe I got on the right track of cleaning these specimens. Thanks to all for the suggestions.

Larry

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