Flash of red when adding SMB

[g_opolis]

I had an unusual thing happen today. I was dropping some gold from an AR solution, and when I added the SMB, it generated a vibrant red color in the liquor for about 5 seconds, and then completely disappeared. I added a little more, and the same thing happened. Would this be a little excess nitric that I missed? There was no out gassing. It seemed like it wanted to drop a red powder for a brief instant, then changed it's mind. Paladium? This was from 40 486 processors. Any comments will be welcomed.

Bye the way: The gold dropped fine, but was a little dark. I've saved all the solutions and rinses.

 

[wop1969]

G, I saw the same thing the other day :shock:

I figured it was normal and I have to many other questions in my head to answer so I did not post about it, but I would like to know what it was

 

[Lou]

This is colloidal gold.

This is also why your gold is dark and probably not aggregating properly to give a spongy precipitate.

 

[g_opolis]

Thanks Lou. It caught me off guard for a minute. The powder is quite loose and dark.

 

[wop1969]

is it good? bad?

if bad what should be done?

 

[lazersteve]

Avoiding colloidal gold is a matter of concentration and purity. The more concentrated and pure you auric chloride solution is the better it will agglomerate into spongy masses. The gold will drop very fast in this form.

Steve

 

[Harold_V]

Avoiding colloidal gold is a matter of concentration and purity. The more concentrated and pure you auric chloride solution is the better it will agglomerate into spongy masses. The gold will drop very fast in this form.

Yep! I have talked often about re-refining my gold in high concentration (about 4 troy ounces/liter). Gold so precipitated comes down very dense and settles quickly.

On rare occasion, the gold precipitated as tiny, glistening crystals, which settled instantly. I used SO2 gas, and experienced the phenomenon only a couple times in my many years. I have no clue why or how.

Harold