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Help Cleaning Brazilian Emeralds

Posted by Terry  
Terry
Help Cleaning Brazilian Emeralds
November 09, 2004 02:35AM
Hey Everyone,
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
Jolyon
Re: Help Cleaning Brazilian Emeralds
November 09, 2004 07:42PM
The white rock is almost certainly quartz (as it's Brazillian, for the Colombian emeralds this would be calcite).

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
Gunnar Färber
Re: Help Cleaning Brazilian Emeralds
November 10, 2004 10:37AM
Hello,

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
Terry
Re: Help Cleaning Brazilian Emeralds
November 10, 2004 07:31PM
I know enough about chemicals to say I know how to handle them. Depending on which chemicals I may not be able to get them without a permit where I live.
LindaA
Re: Help Cleaning Brazilian Emeralds
December 10, 2006 10:09PM
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.
Re: Help Cleaning Brazilian Emeralds
December 10, 2006 10:44PM
    
Gunnar,

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
Re: Help Cleaning Brazilian Emeralds
January 04, 2007 09:18PM
Hi all!


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.
Anonymous User
Re: Help Cleaning Brazilian Emeralds
January 05, 2007 07:10AM
I have some of these emeralds too, and would be very interested in the chemical means to clean them, as dental pick cleaning has not been entirely satisfactory. They are lapidary rough, and the attached bits of matrix are not enough to make the crystals an interesting display.

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
Gerard Martayan
Re: Help Cleaning Brazilian Emeralds
January 05, 2007 10:33AM
I own a few Colombian specimens with the usual black/gray shales and/or calcite matrix.
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
Re: Help Cleaning Brazilian Emeralds
January 07, 2007 02:10PM
Hi all!

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.
Gerard Martayan
Re: Help Cleaning Brazilian Emeralds
January 07, 2007 05:32PM
Thanks Kostas.
You can contact me at
gmartayan@slb.com

Best regards

Gérard
Anonymous User
Re: Help Cleaning Brazilian Emeralds
January 08, 2007 11:00PM
Kostas,

you can contact me at:

tcregOOl (the last three digits are zero zero one) circle-A
earthlink / net

Thank you,

TC
Martin Hanckel
Re: Help Cleaning Brazilian Emeralds
July 01, 2007 12:13PM
I am an industrial chemist and used to handling many acids, such as Hydrofluoric,hydrochloric,sulphuric,nitric, phosphoric and other mixtures.
What acid or acid mixture will clean the matrix from Brazilian emeralds.
Thanks Martin
yahya kader
Re: Help Cleaning Brazilian Emeralds
September 16, 2007 03:35AM
hey i would like to no the name of the chemical u were referring to clean rough emeralds, is it HCL hydrocloric acid??
Elba
Re: Help Cleaning Brazilian Emeralds
April 04, 2008 01:19AM
I have no access to acids, just vinegar. Any tips would be great. It is the first time I am doing this. I am a novice.
Suggestions?

Thanks
El
Re: Help Cleaning Brazilian Emeralds
April 04, 2008 04:12PM
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 of a broken drill bit on a grinding wheel and mounting it with epoxy in a wooden dowel handle.

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
avatar Re: Help Cleaning Brazilian Emeralds
April 05, 2008 07:47PM
    
"I am an industrial chemist and used to handling many acids, such as Hydrofluoric,hydrochloric,sulphuric,nitric, phosphoric and other mixtures.
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.
Joe Moore
Re: Help Cleaning Brazilian Emeralds
April 22, 2008 02:08AM
LindaA Wrote:
-------------------------------------------------------
> 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.
avatar Re: Help Cleaning Brazilian Emeralds
April 22, 2008 04:44AM
    
Most Brazilian emeralds I have seen are in a mica schist matrix. Micas are usually quite resistant to chemical attack, even HF. The only effective method to remove the matrix from around the crystal will be mechanical. Micas are also remarkably flexable, so air abrassives often do very little. What you are looking at is likely hours with a dental pick, or if you have some money to invest, getting a small compressor and a small pneumatic pick or scaler such as those made by Chicago Pneumatic.

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.
avatar Re: Help Cleaning Brazilian Emeralds
May 12, 2008 08:12PM
    
Tim,

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 [back then even kids could buy really neat stuff, no questions asked!] 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

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Claus Hedegaard
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