Acid to dissolve quartz ?

Has anyone here dissolved quartz with hydroflouric acid to obtain the natural form of the gold sample within ?

If you crush the quartz then the gold inside is only worth scrap gold value

I was thinking if the quartz lump was placed into a heavy duty plastic tub and dissolved with acid then the natural shape of the gold inside might have a much higher value for its artistic form ?

It might end up just being thousands of little wafers of gold that are still only worth scrap gold price , or fingers of geometric crystals , or if you're lucky maybe strings of gold crystals that look like the branches of a tree.

Has anyone ever seen this done ?

Is there any other acid used to dissolve rock ?

******* quick note . Hydroflouric acid is extremely dangerous stuff and NOT something you would play with in your backyard ********

edited to remove mondayitis typos

hydrofluoric will break down quartz quite well, and quite quick
problem is getting ahold of some thats is high grade is the hard bit
hydrofluoric acid must be used with care as if you drop it on your skin it will eat away at it really quick and even destroy bone quick.
if you do manage to get some PLEASE use protective gear (gloves, face shield and appren) and DO NOT breath in vapours

XIV said:

hydrofluoric will break down quartz quite well, and quite quick
problem is getting ahold of some thats is high grade is the hard bit
hydrofluoric acid must be used with care as if you drop it on your skin it will eat away at it really quick and even destroy bone quick.
if you do manage to get some PLEASE use protective gear (gloves, face shield and appren) and DO NOT breath in vapours

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yes i was intending to set up a fume hood but dont know yet how to process the fumes in a way to break down their "efficacy"

maybe i can pump the fumes through a filter of some kind that will neutralise the pH . This requires more research.

what i would also like to know , is how much acid is required to dissolve a known mass of quartz,

and find out who takes the used acid for safe disposal and how much it costs to do so

In my dreams if i have 100 kg lump of quartz how many litres of acid would i need ?

I would point out to anyone doing this , that the plastic tub would need to be very thick durable PVC (assuming PVC is non reactive to HFL)

It MUST HAVE a fume hood over it unless you plan to put it way out in the middle of a paddock but that will pollute the ground around it so i wont be going that path.

consider putting a spill bund under the plastic tub in case it splits.

Unless you work in a lab, how are you planning on acquiring the HF?
You need to ask yyourself, is the risk.of using such a dangerous acid and all the setup of tubs, safety gear and ventilators worth the extra $$ you will get from the gold?

If the gold turns out to be just flakes grains and little nuggets then there is no increase in derived value

But if it is unique natural crystaline forms it could be worth 5 times more than gold value

If by some one in a million chance the quartz is removed and it turned out to be tiny fine veins or rivulets of gold say in the shape of a tree then whats your guess on its worth ?

If i break up a test sample and find there is crystaline structure inside it then i would pay a lab to do it for me.

can you suggest the name of any labs who might do this ?
They will already have the OHS compliant setup.

I have no intention of doing something " for a living " that has a risk of killing me.

Hydrofluric acid is dangerous stuff and not recommended. Safest way is use the thermal shock method. Heat the specimen up over a gas burner then drop it in water. The quartz will crack up and go brittle allowing you to pick it away, you might need to do it a few times for big bits.

DD

Try allibrite (Supercheap). Have been told it will clean quartz off but needs to be changed every couple of days & could take a week or longer. I have used it to clean up a specimen but wanted to keep the quartz attached so it only went in for a few hours. Came up good.
For ironstone etc. I have been told brickies acid from Bunnings does the trick but again can take up to a week or longer.
If lucky enough to get a large specimen you may be able to find a "trustworthy" industrial cleaning place with an acid bath? (Or use the thermal shock method above - tried to find some info I had read on this but can't remember where I seen it).
Keep in mind that most specimen gold is worth more than the gold weight also.

you can use hc acid a lot less bad because if you get hc on you you can wash it off and it dosen't eat your skin like hydroflric acid dose it might not eat quartz but it shore makes the gold in the quartz stand out so i would use hc its a lot safer than hf acid and allso use a gas mask be in a well ventilated area and wear acid proof gloves and if you get any acid on you allways have water or a alkaline right next to you

Allibrite is only 1% Hydrofluric acid , it is good for cleaning of small amounts of ironstone and calcrete only. Doesn't really work on quartz, even on little specimens it can take months to eat the quartz and must be changed every couple of days.
I don't believe the myth that specimens are worth heaps more. They are hard to sell because it's difficult to get a accurate weight, even with professional specific gravity tests. I struggle to even get gold value for mine and I sell heaps. I usually just send them whole to the refiners.
The only gold I have found to be worth more the usual is crystalline.

DD

Hunting the yellow said:

you can use hc acid a lot less bad because if you get hc on you you can wash it off and it dosen't eat your skin like hydroflric acid dose it might not eat quartz but it shore makes the gold in the quartz stand out so i would use hc its a lot safer than hf acid and allso use a gas mask be in a well ventilated area and wear acid proof gloves and if you get any acid on you allways have water or a alkaline right next to you

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I have used hydrochloric acid alot for cleaning rusted machine parts . dip it in a 50 % solution of water and HCL and the rust disappears in 10 - 20 minutes , leaving you with beautifully spotless steel

you have to immediately wash it with water , dry it then wipe it over with oil or WD40 though as it will start to rust straight away.

HCL ( Pool cleaner ) is quite cheap but the safety gear is a must have . rubber gloves , full face mask , respirator , hose at the ready , and exit door open . preferably do it outside where the fumes wont damage other goods in the building

I have done this many times but did have a disaster once when the K-Mart plastic tub split and 20 litres of acid spilt all over my workshop floor . took me about 8 hours to clean up the mess with cat litter and mop . not to mention washing the acid off my feet , socks and boots

you couldnt do that with hydroflouric - it would be a dial 000 job for hazmat so these things are not to be messed with

I will do an experiment with quartz and HCL , it would probably work on ironstone - will let you know

Diggerdude said:

Allibrite is only 1% Hydrofluric acid , it is good for cleaning of small amounts of ironstone and calcrete only. Doesn't really work on quartz, even on little specimens it can take months to eat the quartz and must be changed every couple of days.
I don't believe the myth that specimens are worth heaps more. They are hard to sell because it's difficult to get a accurate weight, even with professional specific gravity tests. I struggle to even get gold value for mine and I sell heaps. I usually just send them whole to the refiners.
The only gold I have found to be worth more the usual is crystalline.

DD

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I am not expecting every quartz floater to have crystaline gold , but i am keeping the door open to obtaining a higher price by being creative with its processing if i do find rare bits like that.

If i am in an area where small samples show unique shapes after cracking them open with a hammer then i will try stripping the quartz in a non destructive manner and aim for a value added market.


thanks DD

To dissolve quartz hydrofluric is the only method I have read that works.
If it were me I would'nt play with the stuff, I'd get a quote from a lab if
there were a decent amount.

Ironstone is a different matter, Hydrochloric will dissolve it off very easilly,
not as dangerous a material either.

I like DD's suggestion of thermal shock, would surely get rid of some of it.

There are a few vids on youtube dissolving quartz from silver specimens
in Hydrofluric, all in USA though.

Wish I had this dilemma.

I started the process of getting my poisons license, so I could purchase some HFL acid, but I ended up putting it in the to hard basket,I was told I needed safety showers all the PPE and an OH&S bloke to come and inspect the premises before I could get a license, it was not worth all the effort for the rock I wanted to dissolve.

Diggerdude said:

Allibrite is only 1% Hydrofluric acid , it is good for cleaning of small amounts of ironstone and calcrete only. Doesn't really work on quartz, even on little specimens it can take months to eat the quartz and must be changed every couple of days.
I don't believe the myth that specimens are worth heaps more. They are hard to sell because it's difficult to get a accurate weight, even with professional specific gravity tests. I struggle to even get gold value for mine and I sell heaps. I usually just send them whole to the refiners.
The only gold I have found to be worth more the usual is crystalline.

DD

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Thanks DD - had read on different forums people claim to have dissolved quartz from between 1-3 weeks or longer in Allibrite. Originally I was going to try it but then thought I would keep it as a specimen as it looked ok & I hadn't got one before. Glad I didn't waste my time for weeks on end emptying it out & refilling etc. as even though its only 1% can still be nasty stuff. Will look at thermal shock if I decide to do one down the track.
Again had read elsewhere to not be too hasty in breaking up or dissolving specimens but can see where your coming from. I guess they would depend on whether a collector liked the shape etc. of the specimen to get a bit more for them. Have seen pictures of some nice specimens though that were reportedly worth a bit especially ones attached to other minerals/rock etc. apart from the normal quartz & ironstone.

Cero Mercurio said:

We provide ACID CONTROLLER FOR HF, HCL, H2SO4

you can dissolve Quartz with HF NO SKIN HARMFULL Minimun Order 1000 Litres / 7.99USD x Litre FOB Houston TX.

[email protected]

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Dont think you will sell that much here ( 1000 litres x $7.99 =$7990 ) say $10000 Australian plus freight from USA .

Heatho said:

To dissolve quartz hydrofluric is the only method I have read that works.
If it were me I would'nt play with the stuff, I'd get a quote from a lab if
there were a decent amount.

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This is the best option by far, depending on where you are you could also try the mines department in your state. In WA they have a mines school and may do this as part of their studies?
Try a couple of the many assay labs perhaps.

Peko said:

I started the process of getting my poisons license, so I could purchase some HFL acid, but I ended up putting it in the to hard basket,I was told I needed safety showers all the PPE and an OH&S bloke to come and inspect the premises before I could get a license, it was not worth all the effort for the rock I wanted to dissolve.

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I do OHS for a living and that is just the start of your processes, you will then need to write up all your procedures etc... Fun.
Also PPE is the last on the list of hierarchy controls, so the protection used should be the best you can get.
Bunds, spill control, clean up and disposal, environmental impacts and the list goes on.

PPE at a minimum should be Coveralls (acid resistant), gloves (acid resistant), Full face respirator with acid gas filters, or half mask with face shield and acid gas filters, boots with over guards on them. Even with all that I will would still not handle the stuff. Some things don't give you many chances.

For general chemicals, make sure you cover your eyes/face this is critical. A respirator is a good idea however make sure it has a little carbon in it as well. Work outdoors! or well ventilated but not spreading vapours everywhere.

I use HF (Ali Brite) to clean nuggets coated in ironstone and brings out the gold colour. I use the appropriate safety gear. The plastic container to use is PET plastic such as plastic coke bottles for low concentration HF. I leave the top on lightly to minimise fumes (outside obviously). Nitrile gloves - not latex. Arm and face protection. Finally a tube of Calgonate (Calcium Gluconate) on hand as a just-in-case, just-in-case. Bicarbsoda to neutralise thoroughly when done. Here are two nuggets that were totally encased in ironstone, with very little gold showing through. The crystalline structure inside looks brilliant under high magnification.

I've seen folks shoving their arms shoulder deep into HF, but I certainly wouldn't be ignoring any warnings or precautions it comes with. Its carcenogenic meaning if it doesn't get to you now, it will later from the exposure. I personally don't know the molarity or percentage of HF within AllBrite but hopefully its watered down a fair bit. It is not the same as pure fluoride which is considered safe ( by some ) once in a water solution.
I've always kept these sort of details out of my posts to prevent others copying, especially the younger ones. There's a very easy way to make HF but hopefully this will learn a few not to attempt using it, dont worry about it burning you, worry about it shutting down your organs:

[video=480,360]https://www.youtube.com/watch?v=oipksRhISfM[/video]

AtomRat said:

I've seen folks shoving their arms shoulder deep into HF, but I certainly wouldn't be ignoring any warnings or precautions it comes with. Its carcenogenic meaning if it doesn't get to you now, it will later from the exposure. I personally don't know the molarity or percentage of HF within AllBrite but hopefully its watered down a fair bit. It is not the same as pure fluoride which is considered safe ( by some ) once in a water solution.
I've always kept these sort of details out of my posts to prevent others copying, especially the younger ones. There's a very easy way to make HF but hopefully this will learn a few not to attempt using it, dont worry about it burning you, worry about it shutting down your organs:

[video=480,360]https://www.youtube.com/watch?v=oipksRhISfM[/video]

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If only John Bunting and Robert Wagner watched that video they might not be as infamous as they are :lol:

Come in late on this one, but must comment that Diggerdude is spot on with his thermal shock.

True story - On an old mine field here in Qld, one miner had a shaft that went down 40ft. He was getting 2oz/ton. His method was exactly as DD said. He would burn his quartz, make it brittle, them crush by hand. Just imagine if he had today's knowledge. Maybe 3-4oz/ton? Knowing where he was working and the conditions and the rather primitive methods used, who knows what he would have got.

But back to Headsup - mate, I would categorically say - STAY AWAY FROM HF. It is bloody dangerous and that is an understatement. I've studied in chemistry and use some nasty stuff recovering gold from electronics. I will not let anyone near me when I am processing.



Those brown fumes you see coming in this case from Nitric Acid will kill you. Breath in one gutful and say goodbye. So Headsup, stay away from it unless you are qualified to use these acids safely.