How do i dissolve quartz away from my gold?

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Most use acid bought from the hardware (hydrochloric acid / brickeies acid)

To me your specimen looks like iron pyrite rather than gold, might be a few small bits in it though. Can you put up another picture, in sunlight would be better.
 
Agree with RM that it looks a little like pyrite.
You could try a multi-meter on it.
Pyrite is a semi-conductor and will have a noticeable resistance. Gold will show negligible resistance.
Pyrite is also brittle, so will not scratch with iron (may remove chips though), but will smoothely indent the gold.
Disagree with RM though about Brickies acid (HCl), which may remove traces of ironstone and attack the pyrite (I am told), but will not dissolve quartz.
 
RM Outback said:
Most use acid bought from the hardware (hydrochloric acid / brickeies acid)

To me your specimen looks like iron pyrite rather than gold, might be a few small bits in it though. Can you put up another picture, in sunlight would be better.
Really? I would have thought that would be totally ineffective - absolutely so. The only acid that will dissolve quartz - hydrofluoric- requires a permit, and should not be used outside a fume hood, with gloves and a mask and protective clothing (it does not rapidly show burns on the skin surface, but penetrates the flesh and can dissolve the bones beneath and stop your breathing). Contact with 12 x 12 cm of skin surface can kill (less than the back of your hand). Good for dissolving eyes as well. Don't use it (it requires a lot of it to dissolve the quartz) - some will recommend Alibrite but that contains 1% of that dangerous acid and should be used with protection. . Most other acids won't dissolve gold either - but a mixture of hydrochloric and nitric acid will! So don't use that unless you just want a specimen of quartz.

" a chemist working in Australia was sitting working at a fume cupboard and knocked over a small quantity (100-230 millilitres, about the equivalent of a drinking glass full of water) of hydrofluoric acid onto his lap, splashing both thighs. He immediately washed his legs with water, jumped into a chlorinated swimming pool at the rear of the workplace, and stayed there for about 40 minutes before an ambulance arrived. (Should you ever need to know, the proper treatment for HF exposure is calcium gluconate gel: calcium gluconate reacts very quickly with hydrofluoric acid to form non-toxic calcium fluoride, rendering it harmless.) Sadly, his condition deteriorated in hospital and, despite having his right leg amputated 7 days after the accident, he died from multi-organ failure 15 days after hydrofluoric acid spill. Remember, that was a spill the size of a glass of water".

All chemistry labs that use it have a container of calcium gluconate gel and some calcium gluconate eyewash next to the fume hood, and a shower in the room. I find many people here are quite blas about this horrific acid - I posted a photo of some burns and my entire post warning about HF was deleted by the mods, not just the photos. Here is a url for a photo of a human arm 14 days after a hydrofluoric acid burn (be warned that the mods thought people here could not face such a photo):

http://img.medscape.com/fullsize/migrated/448/393/w448393.fig5b.jpg

Why do you want to dissolve the quartz? If that was gold (which I doubt), it would be a beautiful specimen with the quartz attached. Just a bit of a wash with detergent or something simple to clean any coating on it.
 
Hey GR, if you are talking of HFl, then it will slowly dissolve the quartz, but not the gold as per your second sentence?
I agree that if it was gold, I'd leave it as a specimen!
 
goldierocks said:
RM Outback said:
Most use acid bought from the hardware (hydrochloric acid / brickeies acid)

To me your specimen looks like iron pyrite rather than gold, might be a few small bits in it though. Can you put up another picture, in sunlight would be better.
Really? I would have thought that would be totally ineffective - absolutely so. The only acid that will dissolve quartz requires a permit, and should not be used outside a fume hood, with gloves and a mask and protective clothing (it does not rapidly show burns on the skin surface, but penetrates the flesh and can dissolve the bones beneath and stop your breathing). Don't use it (it requires a lot of it to dissolve the quartz). Most other acids won't dissolve gold either - but a mixture of hydrochloric and nitic acid will! So don't use that unless you just want a specimen of quartz.

Why do you want to dissolve the quartz? If that was gold (which I doubt), it would be a beautiful specimen with the quartz attached. Just a bit of a wash with detergent or something simple to clean any coating on it.

Alibrite a Septone product readily available from most paintshops and many hardware stores without a permit contains Hydrofluoric acid and will dissolve the quartz.

Take a bit of time and you have to regularly change the acid but it does work and works well.
 
This is from the Materials Safety Sheet for Alibrite - take it seriously:

"The effect of HF, i.e. the onset of pain, particularly in dilute solutions, may not be felt for up to 24 hours. It is important that workers have immediate access to the antidote (calcium gluconate) both on and off the worksite in order to apply it as soon as possible. Instructions should be given for the worker not to use the gel in the eye and the worker to still seek medical attention regardless of how minor the contact. The calcium combines with the fluoride to form the insoluble calcium fluoride thus preventing the fluoride from entering the intact skin and causing tissue damage".

What happens if it enters the skin is that you may see no burn and feel no pain for up to a day, but it is attacking the bone beneath. What happens there is that the calcium in your bone is reacting with the Alibrite. Calcium in your blood controls your breathing - as it hits blood vessels it precipitates calcium out of your blood -and you stop breathing. Obviously Alibrite is not as potent as pure HF (1%) but a large spill can have the same effect, and a small spill can put you in hospital.

In deference to the mods sensitivity I include another url here that shows what happens if you splash it on your face - it is gruesome so be warned, but I keep this image in my mind when I use HF (I am a geochemist and use it under all the safety conditions described above, including the gluconate, shower, fume hood and complete protective clothing and face mask). I am not doing this to horrify you, but I have seen very casual comments on this site about using HF.

http://1.bp.blogspot.com/-LSUPD6ygzn8/Uh2LUHknEGI/AAAAAAAAAMs/LsLBRViH404/s640/eye2.jpg

I once had a driller splash it in his eye, and the memory remains.
 
BigWave said:
Hey GR, if you are talking of HFl, then it will slowly dissolve the quartz, but not the gold as per your second sentence?
I agree that if it was gold, I'd leave it as a specimen!
Thanks - that was a typo and it was soon enough that I could correct it.
 
Thought so, but have never seen you make a mistake before, so I could have been wrong.
PS: I was actually wrong once, but that was when I thought I was wrong, but wasn't :cool:
 
As with Mercury, as with most acids, as with guns, pointy sticks, sharp implements and electrical items, common sense and a bit of PPE is required.

Unfortunately there's always someone who thinks we are not capable of exercising due care with things that can harm us.

Alibrite is perfectly fine if you read the instructions and use due care.
 
madtuna said:
As with Mercury, as with most acids, as with guns, pointy sticks, sharp implements and electrical items, common sense and a bit of PPE is required.

Unfortunately there's always someone who thinks we are not capable of exercising due care with things that can harm us.

Alibrite is perfectly fine if you read the instructions and use due care.
I would use Alibrite with gloves and goggles outside a fume hood (as I said it is 1% and a different situation to the pure acid)- but I would not dream of using hydrofluoric acid that way. My comments particularly related to that. Some universities will not even allow hydrofluoric acid to be used in any of their laboratories on campus - not allowed on campus at all. Yet I see prospectors using it with just rubber gloves. However the reference in italics that I gave above was from the Alibrite instructions (it was referring to the HF in Alibrite, and referring to Alibrite when it talked about the dangers of being unaware when using dilute solutions.- it also says "A First Aid Kit should be readily available in case of injury caused by this product. This kit should contain: * 3% Calcium Gluconate gel (for skin injuries)" Good to hear that you take this precaution.

" A standard geology technique, which involved the dissolving of sedimentary rock with mineral acids (hydrochloric and hydrofluoric acid), was being undertaken in a fume cupboard" - that is the beginning of the description of the death of the technician who died despite diving in the swimming pool - it was a trained geological technician in Perth. "Investigation showed that this death could have been prevented if adequate personal protective equipment had been worn during the handling of concentrated hydrofluoric acid. Full length PVC coveralls with sleeves to the wrist or a full-length PVC apron with sleeve protectors, a face shield, rubber boots, safety goggles and mid-arm length PVC gloves should have been worn by the deceased when HF was being used in the fume cupboard. The deceased did not have access to an emergency shower to remove the HF, instead the skin was washed from a hose that provided water at a very low flow rate. Because of the low flow rate, the volume of water may have spread the HF onto other parts of the skin".

My driller was not dumb either, and had been instructed in the dangers of HF If everyone feels they know better, fine, but I am willing to bet that only a few percent of people using this site would be aware that an acid that they only spilt over their skin on the back of their hand, that was not hurting, and was not showing a burn, might already be killing them. It is not a normal acid like hydrofluoric, sulphuric or nitric, where even the fumes warn you that they will burn you - and nobody dies from those acids because they spilt some over the back of their hand, as nasty as the experience may be. A person cannot intuitively know such things (which is why we have OH&S, and why people who ignore it have nasty accidents and don't get a job from me under any circumstances - or with any mining company or laboratory). I spend my life working with such things, and also perchloric acid and radioactive substances and X-rays and I can assure you that highly trained people, taking normal precautions, still have regular accidents - I have had a number of friends, and even more acquaintances, killed by such things (all of them highly trained chemists and physicists).
However, yes, if you have to do it, Alibrite is not as dangerous, but needs care.
 
goldierocks said:
madtuna said:
As with Mercury, as with most acids, as with guns, pointy sticks, sharp implements and electrical items, common sense and a bit of PPE is required.

Unfortunately there's always someone who thinks we are not capable of exercising due care with things that can harm us.

Alibrite is perfectly fine if you read the instructions and use due care.
I would use Alibrite with gloves and goggles outside a fume hood (as I said it is 1% and a different situation to the pure acid)- but I would not dream of using hydrofluoric acid that way. My comments particularly related to that. Some universities will not even allow hydrofluoric acid to be used in any of their laboratories on campus - not allowed on campus at all. Yet I see prospectors using it with just rubber gloves. However the reference in italics that I gave above was from the Alibrite instructions (it was referring to the HF in Alibrite, and referring to Alibrite when it talked about the dangers of being unaware when using dilute solutions.- it also says "A First Aid Kit should be readily available in case of injury caused by this product. This kit should contain: * 3% Calcium Gluconate gel (for skin injuries)" Good to hear that you take this precaution.

" A standard geology technique, which involved the dissolving of sedimentary rock with mineral acids (hydrochloric and hydrofluoric acid), was being undertaken in a fume cupboard" - that is the beginning of the description of the death of the technician who died despite diving in the swimming pool - it was a trained geological technician in Perth. "Investigation showed that this death could have been prevented if adequate personal protective equipment had been worn during the handling of concentrated hydrofluoric acid. Full length PVC coveralls with sleeves to the wrist or a full-length PVC apron with sleeve protectors, a face shield, rubber boots, safety goggles and mid-arm length PVC gloves should have been worn by the deceased when HF was being used in the fume cupboard. The deceased did not have access to an emergency shower to remove the HF, instead the skin was washed from a hose that provided water at a very low flow rate. Because of the low flow rate, the volume of water may have spread the HF onto other parts of the skin".

My driller was not dumb either, and had been instructed in the dangers of HF If everyone feels they know better, fine, but I am willing to bet that only a few percent of people using this site would be aware that an acid that they only spilt over their skin on the back of their hand, that was not hurting, and was not showing a burn, might already be killing them. It is not a normal acid like hydrofluoric, sulphuric or nitric, where even the fumes warn you that they will burn you - and nobody dies from those acids because they spilt some over the back of their hand, as nasty as the experience may be. A person cannot intuitively know such things (which is why we have OH&S, and why people who ignore it have nasty accidents and don't get a job from me under any circumstances - or with any mining company or laboratory). I spend my life working with such things, and also perchloric acid and radioactive substances and X-rays and I can assure you that highly trained people, taking normal precautions, still have regular accidents - I have had a number of friends, and even more acquaintances, killed by such things (all of them highly trained chemists and physicists).
However, yes, if you have to do it, Alibrite is not as dangerous, but needs care.

Good post, and you are totally right about HF Acid.
Its used in the water Industry to put Flouride in drinking water and its very dangerous!
Have done the training on it. Its a struggle finding anyone wanting to go near a Flouride plant, nasty stuff.
A workmate has had his work supplied prescription glasses get etched from only going into the plant room a few times?
A plant built in 2009 is rusting away and looks like parts of the Titanic internally.

As far as OHS goes its like entering the disabled reactor at Chernobyl.
 
Swinging & digging said:
goldierocks said:
madtuna said:
As with Mercury, as with most acids, as with guns, pointy sticks, sharp implements and electrical items, common sense and a bit of PPE is required.

Unfortunately there's always someone who thinks we are not capable of exercising due care with things that can harm us.

Alibrite is perfectly fine if you read the instructions and use due care.
I would use Alibrite with gloves and goggles outside a fume hood (as I said it is 1% and a different situation to the pure acid)- but I would not dream of using hydrofluoric acid that way. My comments particularly related to that. Some universities will not even allow hydrofluoric acid to be used in any of their laboratories on campus - not allowed on campus at all. Yet I see prospectors using it with just rubber gloves. However the reference in italics that I gave above was from the Alibrite instructions (it was referring to the HF in Alibrite, and referring to Alibrite when it talked about the dangers of being unaware when using dilute solutions.- it also says "A First Aid Kit should be readily available in case of injury caused by this product. This kit should contain: * 3% Calcium Gluconate gel (for skin injuries)" Good to hear that you take this precaution.

" A standard geology technique, which involved the dissolving of sedimentary rock with mineral acids (hydrochloric and hydrofluoric acid), was being undertaken in a fume cupboard" - that is the beginning of the description of the death of the technician who died despite diving in the swimming pool - it was a trained geological technician in Perth. "Investigation showed that this death could have been prevented if adequate personal protective equipment had been worn during the handling of concentrated hydrofluoric acid. Full length PVC coveralls with sleeves to the wrist or a full-length PVC apron with sleeve protectors, a face shield, rubber boots, safety goggles and mid-arm length PVC gloves should have been worn by the deceased when HF was being used in the fume cupboard. The deceased did not have access to an emergency shower to remove the HF, instead the skin was washed from a hose that provided water at a very low flow rate. Because of the low flow rate, the volume of water may have spread the HF onto other parts of the skin".

My driller was not dumb either, and had been instructed in the dangers of HF If everyone feels they know better, fine, but I am willing to bet that only a few percent of people using this site would be aware that an acid that they only spilt over their skin on the back of their hand, that was not hurting, and was not showing a burn, might already be killing them. It is not a normal acid like hydrofluoric, sulphuric or nitric, where even the fumes warn you that they will burn you - and nobody dies from those acids because they spilt some over the back of their hand, as nasty as the experience may be. A person cannot intuitively know such things (which is why we have OH&S, and why people who ignore it have nasty accidents and don't get a job from me under any circumstances - or with any mining company or laboratory). I spend my life working with such things, and also perchloric acid and radioactive substances and X-rays and I can assure you that highly trained people, taking normal precautions, still have regular accidents - I have had a number of friends, and even more acquaintances, killed by such things (all of them highly trained chemists and physicists).
However, yes, if you have to do it, Alibrite is not as dangerous, but needs care.

Good post, and you are totally right about HF Acid.
Its used in the water Industry to put Flouride in drinking water and its very dangerous!
Have done the training on it. Its a struggle finding anyone wanting to go near a Flouride plant, nasty stuff.
A workmate has had his work supplied prescription glasses get etched from only going into the plant room a few times?
A plant built in 2009 is rusting away and looks like parts of the Titanic internally.

As far as OHS goes its like entering the disabled reactor at Chernobyl.
I agree - I use it under stringent conditions and have done so for 50 years, but I am still always a little nervous.
 
With all due respect GR, anytime someone mentions either HF or Mercury immediately someone will jump on and tell us of the dangers, post the MSDS and treat us like clueless idiots. You are not the first nor will you be the last. It does get tiring though.

I am referring to Alibrite available to the public, not pure HF which as you state requires a permit.

Alibrite will work fine for what the lady wants to do if it is in fact gold in her quartz. Yes care and PPE needs to be taken but it works and works well. Nobody is recommending she try and access undiluted HF.
You might call that blas or casual, that's up to you. But it's fact.

And yes, I do have a tube of Calcium Gluconate gel along with a load of other first aid stuff I hope to never have to use.
 
madtuna said:
With all due respect GR, anytime someone mentions either HF or Mercury immediately someone will jump on and tell us of the dangers, post the MSDS and treat us like clueless idiots. You are not the first nor will you be the last. It does get tiring though.

I am referring to Alibrite available to the public, not pure HF which as you state requires a permit.

Alibrite will work fine for what the lady wants to do if it is in fact gold in her quartz. Yes care and PPE needs to be taken but it works and works well. Nobody is recommending she try and access undiluted HF.
You might call that blas or casual, that's up to you. But it's fact.

And yes, I do have a tube of Calcium Gluconate gel along with a load of other first aid stuff I hope to never have to use.
Good, then you are sensible. I have seen scores of people here recommending use of Alibrite but you are the first to mention having calcium gluconate - how many do you think use it? But good for you that you have checked.

And although HF requires a permit, I see people in possession of it, it is not that difficult to get from others, and there is frequent reference to people using it for exactly this purpose. I was replying to someone who obviously does not know because they asked the question, and HF was the (only) answer to what dissolves quartz - whether pure HF or the HF in Alibrite. It was not a specific discussion of Alibrite but an answer to a question - before you gave your contribution about objecting to people being given safety advice. You don't have to read it if you already know, and if you think most prospectors know you are kidding yourself. I find such unnecessary replies also tiresome, but everyone varies.
 

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