Gold

[Brandt]

Have some gold that wont disolve in AQ form a white precip on out side soaked in nitric first wasnt silver.??? Thanks

 

[g_axelsson]

Sounds like a gold and silver alloy to me.
- If you have too high amount of silver when trying to dissolve it in AR then it will form a white coating of silver chloride and protect the gold from the AR.
- If you have too high amount of gold when trying to dissolve the silver in nitric acid then the gold will cover the silver and protect it from the nitric acid.
The two areas is overlapping so the proper way to deal with your problem is to use inquartation. Melt your gold with enough silver to get the gold content down to 10 karat or lower, then you can dissolve the silver and other base metals with nitric acid. After washing the remaining gold powder you process that with AR to dissolve and refine it.

For detailed descriptions of inquartation use the search function or read Hoke's book.

/Göran

 

[Brandt]

Thanks ill try that have always inquarted but this came from a friend in calif from some creek down there.