What happened??????

[Paige]

I put three pieces of 14kt gold in HCL+Cl (bleach). Hit it with a little heat.
After 24 hours, have a beaker with green fluid (copper?) and a clear, crusty sludge over the pieces. I took the pieces out rinsed them wioth water, and they look purer than they started, will hit them with a Mizar, shortly. The crusty clear stuff dissolved in H20, and turned milky white.

Did I manage to leach some copper out and something else? The pieces are fragile now. (I was trying to avoid using nitric & AR).

What happened?

Dumb Paige

Tested pieces with Mizar. Some tested 16kt., some 14kt., some "not gold" (when I was trying to get a double dip outta one dropping of Mizar solution). All pieces now look more like fine gold than shiney 14kt jewelry.

 

[lazersteve]

Did you test the solution to see if it had absorbed any gold?

The process is not really effective on karated gold unless it is properly prepared via inquarting.

The film and powder were probably silver chloride.

Steve

 

[goldsilverpro]

I think that the gold looking richer is a surface phenomenon.

If it is more fragile now, it sounds like the gold is dissolving.

The crusty stuff that slimes off white, with water, is silver chloride. When you're using any form of HCl on karat gold, you'll always have silver chloride. The thicker it gets, the more it slows down the reaction. You did right in rinsing it off. However, save your rinses. They not only contain silver chloride but, they are wet from the gold bearing acid solution.

Other ways of removing silver chloride: crush it off and then rinse it; dissolve it with warm household ammonia (acidify it with HCl, shortly after it cools, to prevent the formation of silver azides); dissolve it in fairly strong photo hypo (sodium thiosulfate).

Add a little more bleach every so often.