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Techniques for CollectorsHelp Cleaning Brazilian Emeralds
9th Nov 2004 02:35 UTCTerry
I purchased some mine rough emeralds on Ebay so I could say, I have emeralds in my collection, my question is , what would be the best way to remove some or all of the surrounding rock matrix, for the most part it appears to be mica, one large piece seems to have a white rock under the dark mica layer, along with some nice emerald crystals.
Thank you
Terry
9th Nov 2004 19:42 UTCJolyon
THe best way to remove this is by hand using a steel dental pick and scraping away carefully at the mica to reveal the crystals.
Jolyon
10th Nov 2004 10:37 UTCGunnar Färber
It give a way to do it. But before I tell it you, I have to know how profesional you in the handling of dangerous chemicals. It give also a very good mechanical way, but for it you need a very good equipment.
Best Regards
Gunnar
4th Sep 2020 23:34 UTCMark angelo canova
10th Nov 2004 19:31 UTCTerry
10th Dec 2006 22:09 UTCLindaA
10th Dec 2006 22:44 UTCBarry Flannery Expert
Do not suggest that chemical as unless he is a phD Chemist or has access to a laboratory he shouldn't be using it!
Barry
4th Jan 2007 21:18 UTCAnonymous User
First of all,why to remove the matrix?In general it is thought the best specimens are either floaters or have a nice matrix so the display beautifuly!Take my advice and do not remove the matrix.I would suggest a trim work on the specimen so that the emeralds are better seen.This has to be done very carefully,with metallic tools,always removing(braking) a small piece of the matrix and trying not to harm(brake)the emeralds.There is always the option trading these emeralds for emerald crystals and do not destroy the specimens by removing the matrix.
However,if you insist on removing the matrix,you have to do the following:
1-Carry your emeralds to a specialist for diagnosis(identification) of the matrix mineral(s).
2-Then goes the chemical removement.This is a very dangerous process,so do not be mad to the guys who do not want to tell you about it.I hope i can convince you by saying that a tiny drop of this acid fell close to my eye!1 cm saved me of losing my eye-I was very lucky!!!So,if you are not a specialist,or very familiar to the chemicals,do not risk your life,it's more important than emeralds.Go to you local museum(where you may have a specialist make the diagnosis)and ask a specialist do the job for you.
Anyway,I can tell you which chemicals to use and how,but think about it very seriously before you ask me to.Otherwise,I'd be glad to help.
regards!
-Kostas.
4th Sep 2020 23:38 UTCMark angelo canova
5th Jan 2007 07:10 UTCAnonymous User
I understand the concern that keeps the formula off a public board like this. While he does not have a PhD, my brother is a certified haz-chemical handler (he works for a semiconductor factory), and has agreed to perform the cleaning for me, even if it is HF or HBF, in the proper manner. How can I contact you for the cleaning formula?
Thanks
TKC
5th Jan 2007 10:33 UTCGerard Martayan
Emerald crystals are partly embedded in the shale and/or in the calcite and I'm tempted
to trim some crystals so they can be better seen.
Are metallic tools the only recommended way to go for a trimming work on "Colombian" matrix?
Thanks
GM
7th Jan 2007 14:10 UTCAnonymous User
Yes,no problem,fell free to contact me,I just do not guarantee success,I hasn't try it myself on my emerald.Note that if we're talking about quartz,it's dissolvable nearly to any acid instead of one.But,since beryl(emerald) is totally non-dissolvable in any acids,you can give it a try!
Please let met know your email,so I can let you know.
Best regards,
-Kostas.
4th Sep 2020 23:39 UTCMark angelo canova
7th Jan 2007 17:32 UTCGerard Martayan
You can contact me at
gmartayan@slb.com
Best regards
Gérard
8th Jan 2007 23:00 UTCAnonymous User
you can contact me at:
tcregOOl (the last three digits are zero zero one) circle-A
earthlink / net
Thank you,
TC
1st Jul 2007 13:13 UTCMartin Hanckel
What acid or acid mixture will clean the matrix from Brazilian emeralds.
Thanks Martin
16th Sep 2007 04:35 UTCyahya kader
4th Apr 2008 02:19 UTCElba
Suggestions?
Thanks
El
4th Apr 2008 17:12 UTCTim Jokela Jr
When that grows dull, graduate to a Foredom or Dremel tool for speedy matrix removal. Protect your eyes and your lungs!
A fair number of people tumble the stuff, but it takes some time.
Using vicious acids like HF on ten buck a pound stuff is madness. One drop on your skin and it eats right down to bone... and you can't wash it off... sound fun?
T
5th Apr 2008 20:47 UTCPeter Haas
What acid or acid mixture will clean the matrix from Brazilian emeralds."
If you are, it should be easy as pie for you to find that out.
22nd Apr 2008 03:08 UTCJoe Moore
-------------------------------------------------------
> I also have rough emeralds. Most of the ones I
> have are in a iron matrix. Very dirty and I have
> use muractic and also battery acid, not together.
> This works pretty good, but I'm also looking for a
> better way to clean them before i try faceting
> them. Any suggestions out there.
I soak mine in oxalic acid; it takes awhile, usually about a monyh of soaking but works great and is gentle. I agitate my jars every few days and watch the inprovement. I buy mine in crystal form so I can control the potency.
22nd Apr 2008 05:44 UTCJesse Fisher Expert
Chemicals such as HCL and oxalic acid may be useful in removing iron stain or any carbonates that may be in the matrix, but will have no effect on the mica.
12th May 2008 21:12 UTCClaus Hedegaard
Sorry to pick on you, but you present a common, misguided fear:
> I'd suggest that Brazilian mine run emerald isn't
> worth risking life and limb over. You can make an
> excellent probe tool by sharpening the butt-end
Chemicals as such are not dangerous and you do not 'risk life and limb' by responsible use of chemicals any more than you do by mechanical tools, possibly even less.
I started using chemicals when I turned 10 and now I have little letters after my name. I never had any problems with chemicals but have seriously injured myself using hammer, chissel, hydraulic splitter and other mechanic tools. Yes, I had proper instruction & guidance before using either.
Chemicals are the right solution to many problems - cleaning minerals & others. Ask people and have somebody show you before you start and do not experiment on your best piece. Evidently use gloves, ventilation, proper vessels, etc.
Honestly, who in his/her right mind would ever enter a mine, given all the potential dangers? Don't be stupid and be informed before you start, but do not let fearmongering prevent proper use.
Claus
6th Feb 2009 16:01 UTCJohn Hayes
5th Mar 2009 08:36 UTCRock Currier Expert
You will need to post a picture of your EBay emeralds. With a picture to work from and to ask questions about you will probably get a much more focused response to your question and a much better chance of improving the value of your specimens.
12th Aug 2009 04:29 UTCPTF
The gemologist also said I could tumble them with sand and that would wear away the shist. I don't have a tumbler so that isn't an option right now.
How did yours turn out?
PTF
12th Aug 2009 13:29 UTCScott Sadlocha
The samples I have are most likely Brazilian, and look to be in a mica schist matrix as mentioned by someone else. I am at work now, but I will try to post a picture later today when I am at home. I know they are really not worth much, and just want to clean some of the matrix off to get a better idea of the crystals/structure, as well as practice my trimming skills.
One other thing I have noticed with them, is the fact that they have a strong odor of oil or petroleum. I figure that this is the result of their extraction method, in that some type of tool was used as well as a lubricant. I am just curious if there is some easy way to clear the smell from them. Thanks-
12th Aug 2009 14:33 UTCDavid Von Bargen Manager
One other thing I have noticed with them, is the fact that they have a strong odor of oil or petroleum. I figure that this is the result of their extraction method, in that some type of tool was used as well as a lubricant. I am just curious if there is some easy way to clear the smell from them.
Nope, oil is sometimes used as a "filler" to make the stones look better.
http://www.ganoksin.com/orchid/archive/199812/msg00094.htm
14th Sep 2009 04:08 UTCTim Jokela Jr
Though of course I may be mistaken, and they have a nice little lab in the backyard, complete with fume hood, quality safety gear, and waste disposal procedures. Backed up by some education and hopefully that ever so rare ingredient these days, common sense.
I don't want to get into a huge discussion about relative risks, but some would say there's little to no risk in the average mine. Call me a paranoid fearmonger, but look at it this way: we live in a world where people severely burn themselves with cups of coffee, then sue for millions.
So no, let's not encourage folks to go out and play with HF to make semi-attractive green rocks slightly more attractive.
(No disrespect to Brazilian emeralds, I just bought a couple, but they certainly don't compare to Colombian, for which I would gladly perform my chainsaw-juggling act, blindfolded, on a tight-rope, over a pool of acid, while drinking extremely hot coffee.)
T
10th Nov 2009 22:20 UTCPT
Thanks.
PT
11th Nov 2009 04:43 UTCRock Currier Expert
9th Mar 2010 23:03 UTCJust a beginner
10th Mar 2010 23:46 UTCAdam Kelly
First off, are they facet grade?
If not, are thet cab grade?
How many do you have?
Where are you located?
Could you post a picture of the emeralds?
3rd May 2010 20:38 UTCJulia
12th Dec 2012 19:36 UTCdoug elenbaas
12th Dec 2012 22:34 UTCRock Currier Expert
17th Oct 2015 10:42 UTCRajendrasinh
18th Sep 2021 19:55 UTCVirginia Stonehouse
17th Oct 2015 14:07 UTCWayne Corwin
Clear them of what?
17th Oct 2015 17:26 UTCReiner Mielke Expert
20th Apr 2016 15:02 UTCMeyeusername
11th Jan 2017 15:05 UTCJean Coulombe
Rock polisher: buy a good one. The ones you get at a walmart-type store are usually a total waste of money. Look on ebay to get an idea of what a proper one looks like (price range: $100 to $500, varies according to volume that can be treated at once and motor strength). IMPORTANT: a rock tumbler turns slowly and needs time to do a good job; the cheap ones turn too quickly.
Cleaning emeralds with acids:
Don't use ANYTHING with fluorite - hydrofluoric acid reacts with beryl and will probably damage your stone way beyond repairable.
Muriatic acid (the stuff used to clean basement cement floors) is a good agent. But, like any acid, wear proper equipment. Read the instructions, understand them, follow them, and take ALL the necessary precautions (like working in a well ventilated area, wearing goggles, and adding water to acid - and not the other way around). Muriatic acid emits fumes: if there is any metal around and you are working in an enclosed environment, the metal will be corroded over a somewhat short period of time. Iron and steel will rust, and aluminium will become crumbly. I ruined a $50 router bit finding that fact out.
Sulfuric acid is supposed to work better, but I need a permit to acquire some, so I haven't had a chance to check it out.
Make sure you neutralize the acid after you are done (adding water only weakens it). A base will do (baking soda works fine).
If you are uncomfortable using acids, don't use them. Their mishandling can lead to extremely serious problems (including breathing and other health issues).
Rotary tools (Dremel, Foredom): get one with a strong motor. Foredom uses 1/3 HP motors, which can be used all day long. Dremel uses mostly 1/6 HP motors, which are designed for short light use. If you use a light motor for hours on end, you will quickly burn it.
For emerald cleaning, I use the green (corundum) rotary heads (not the polishing ones, which contain rubber and wear away within seconds). They take away the black matrix rather easily, but, because their hardness is not much higher than that of emerald, they slide across the emerald a lot without damaging it (when putting medium to light pressure on the tool). You may use diamond heads, but they chew right through emerald; not a good thing - I've ruined a bit of nice rough learning that.
Blue ceramic heads don't work at all on emerald: you might as well take your money and flush it - you'll save yourself a trip to the store and some aggravation.
If you decide to use diamond heads, go sintered. The plating on plated heads wears out quickly and tends to peel.
For best results with a rotary tool, try grinding away with the material and the head under water (1/2 inch below the surface is plenty), in order to dissipate the heat and contain the dust. You will get water spray once in a while. Please note that water might stay on the head after you are done, or even get into the rotary tool shaft while in use and rust away the cable inside. So, make sure to dry everything up after use, and to do the proper maintenance a bit more often than regularly.
Using a rotary tools requires patience (like anything else in the rock, gem and minerals field). As soon as you start using excessive force, you've got problems coming up.
Hope all of this is of some use.
11th Jan 2017 15:40 UTCDon Saathoff Expert
11th Jan 2017 16:08 UTCD. Peck
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Copyright © mindat.org and the Hudson Institute of Mineralogy 1993-2024, except where stated. Most political location boundaries are © OpenStreetMap contributors. Mindat.org relies on the contributions of thousands of members and supporters. Founded in 2000 by Jolyon Ralph.
Privacy Policy - Terms & Conditions - Contact Us / DMCA issues - Report a bug/vulnerability Current server date and time: May 9, 2024 21:32:36