My guess:
Picture1: you left an excess of nitric in solution
Picture2: the SO2 from SMB reduced some of the gold to colloidal gold (purple)
Picture3: the excess nitric redissolved the gold
Picture4: the excess nitric is gone, probably due to adding large excess of smb, so the gold precipitated and redissolved until all excess nitric was gone, the blue color shows, that all gold is precipitated, but you can't see any gold, because it has just been a tiny amount. It is only a tiny amount, because you dissolved gold plated in AR - lots of basemetals with only traces of gold.
Just a guess, that fits to what you wrote and showed and based on what I assume you have done.
Btw. this drinking glass is a big NO! The colored solutions just look like some juice! I really hope, you are not doing this in your home or even in your kitchen!
All in all, this is not how things are done properly. Beside the safety, we try to avoid dissolving basemetal along with gold, - as far as possible. There are two ways you can choose. Remove base metals first mechanically, then wet chemically, leaving mostly gold to refine in a second process. Or, you choose a selective method to get the gold and leave the base metals. One of those is the sulfuric cell. And then refine the recovered impure gold powder.
Further you have to test before and after all steps. This can only be done properly if you have a gold solution to test your stannous and if you did not overuse smb. A high excess of SO2 will give a false positive, because SnCl2 is reducing SO2 to H2S (Wiberg, Inorganic chemistry), which will precipitate (among others) brown SnS even under strongly acid conditions
(fx. at cSn=10-4 mol / L it will precipitate at pH >0.35) - just my explanation for the false positive, which not has been disproved so far.
I searched for "hoke" in your posts so far without any result. Your questions in the other threads and the fact you never mentioned Hoke leads me to assume you did not do your homework. Reading Hoke is essential. If you haven't, then you would be well advised to stop your experiments and read.
, again as i was working with AR solution dissolving some gold plated i use sodium metabisulfite to precipitate like usual 8) , but something bizard has happened ....the solution turn to little brown yellowish, when i add little mor SMB it turn to black reddish then it turn back to yellow ....here is the photo...............what did i wrong ?
