# black powder from silver



## totob (Mar 10, 2014)

Hello all
I placed old silver jewelry in nitric acid, I noticed a considerable amount of black powder not dissolved.
What is this substance?
Thank you


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## justinhcase (Mar 10, 2014)

If you are really lucky you have found some of the fabled Platinum impurity's in old silver,or it is silver that has cemented out of your solution when other things alloyed with it have been dissolved .most lightly it is mostly dirty impurity's mixed with the two latter.
Hope you are doing that out doors away from habitation's or in a fume hood.


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## totob (Mar 10, 2014)

justinhcase said:


> If you are really lucky you have found some of the fabled Platinum impurity's in old silver,or it is silver that has cemented out of your solution when other things alloyed with it have been dissolved .most lightly it is mostly dirty impurity's mixed with the two latter.
> Hope you are doing that out doors away from habitation's or in a fume hood.



thank you for reply
when i put the black powder in fresh nitric acid not dissolved.
i doing it out door


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## justinhcase (Mar 10, 2014)

Well if you are not doing tens of kilos I would just call it junk and read up safety then on cementing silver with copper.
Then find a safe way to melt the cemented silver into a bar(I used an oxy acetylene torch from the farm next door for years so find a friend with a garage or good work shop before you go mad on kit.)
Then read up on electro cell's.
All very easy and great fun.


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## kurtak (Mar 10, 2014)

justinhcase said:


> If you are really lucky you have found some of the fabled Platinum impurity's in old silver,.



actually PGMs when alloyed with silver will go into solution along with the silver - they then come back out of solution along with the silver when you cement the silver - the PGMs are then recovered when you run the silver in the silver cell

Nitric normally wont touch Pt & is "very" slow to react with Pd --- except when they are alloyed with silver - then they are both very much attacked by nitric 

So I doubt its PGMs - being jewelry I would guess dirt &/or other organics but that's just a guess not knowing more about what it looked like to start with &/or how it was handled before processing

Kurt


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## nickvc (Mar 10, 2014)

If any value is likely to be there it's gold, try the black powder in AR and test with stannous.


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## kurtak (Mar 10, 2014)

nickvc said:


> If any value is likely to be there it's gold, try the black powder in AR and test with stannous.



that is "possible"


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## justinhcase (Mar 10, 2014)

good job I never throw any of mine away.
now I have progressed to you people I can see if there is any thing interesting in it.
Never heard of gold being mixed up with silver only Pt.
Have you ever used A.R. totob?if not I would wait until you have studied it before jumping from silver to something that advanced.
For now ither call it junk or keep it for latter as it may yet be of interest.
P.S. Thank's for reminding me about the alloyed affect of PT+Ag with nitric ,I knew but was having one of my blond moments.DoW!!


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## totob (Mar 10, 2014)

nickvc said:


> If any value is likely to be there it's gold, try the black powder in AR and test with stannous.


ok i will do


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## solar_plasma (Mar 10, 2014)

justinhcase said:


> ...
> Never heard of gold being mixed up with silver only Pt.
> ....



I can't find the thread, but someone on the forum processed very old sterling, which he had gotten back from an unsatisfied customer and if I remember right, he got something about 1g gold/kg of this sterling.


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## justinhcase (Mar 10, 2014)

Nice lucky man.
Wish some one would sell me kit like that.
The only time I see any thing like that is heavily gilded items.
Such items are always lovely and I do hope no one has ever recycled any of them.
Some time's it is very hard to see but that can be fixed.


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## totob (Mar 12, 2014)

I've put the powder in AR solution but did not dissolved so it's just junk.


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## justinhcase (Mar 13, 2014)

Good stuff.
Have you read up on stannous chloride test's.
You may not have found enough to observe dissolving but may be able to detect trace amounts.
Which is always good practices to do.I have just found my first little bit of Pt but in some jewellery scrap.
Got to love ms Hoke.


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