Gold nugget Tarnished

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valicek

Member
Joined
Jul 3, 2021
Messages
14
Hi all, I'm hoping to get some advice on how to correct a reaction that happened while I was trying to clean a nugget. I put the nugget in nitric acid but now half of it is black. I think there may have been residual hydrochloric acid in the jar that may have mucked it up. Any help would be great because it's a nice nugget and I'd hate to have to aqua regia it
Cheers
 
If hydrochloric acid is present, then it is gold precipitate over a reducer, most probably iron compound. If you boil it in hydrochloric acid (after water rinse) it may remove the iron as well as other minerals shown
 
Fantastic Lino, it is working. It's been boiling for 2.5 hours now In hydrochloric acid after boiling in water. It's about 80% done now. I assume I keep boiling until nugget boils no more? Thanks so much for your knowledge 🍻 PS I'll take photos of finished product tomorrow
 
Hi Lino, I've boiled in hydrochloric for about 4 hours but it hasn't quite got the gold colour on that darker side. Do I reboil until gone or is it time for something else? Much appreciate any input.
 

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Thanks for your reply Lino, so pure ammonia into a beaker and let it sit for how long approximately? I'm assuming I do not add heat as it's boiling point is -33 degrees. Thanks again
 
NICE looking nugget :shock: 8) :G :!: :mrgreen:

How much does it weigh :?:

Looks like it is "about" 70 -80 % gold with 20 - 30 quartz :?:

Kurt
 
Hi Kurt, it weighs 23.8g. I haven't done specific gravity yet but will do and will post results. 🍻
 
It turns out I went with a hot caustic bath. Boiled in a strong +60% for an hour With no real difference. Any thoughts?
 
On closer inspection there is alot of new cavities and alot more sharp edges. So the hot caustic definitely did something but it has not taken off the dull look on one side. Any thoughts always appreciated
 
It's way more porous and it looks a bit rusty to the eye. Another water boil and hydrochloric
boil ?
 
Ok, now after water boil and then hydrochloric again I was inspecting the nugget and it broke into 3 main chunks and bit coming off. I guess the treatments has eaten away all of the structure that was holding the gold together. Anyway I'm gutted but not too bad. Still would like to make it glisten so any help is appreciated.
I did specific gravity and it's got 20.2g of gold in it.
 
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