Should my powder look like this....

[Rmwatson78]

I recently found some old agua regia solution in a bucket that I couldn't quite remember how I got and it tested positive for gold. I tested the pH and it was <0, so I used urea to bring the pH to like a 1 and then used oxalic acid and a submersible heater to try and precipitate the gold. I used a 2.5cfm vacuum pump and a 2 liter buchner funnel to filter the powder that dropped and it seemed to be super thick, heavy and dense as I scraped it out of the funnel. I got a really heavy and dense greenish yellow powder in the end. The other powders I have seen around here that the experts seem to say look good are more orange in color. Can anyone tell me what I might have missed or how I should correct it from here?

 

[MGH]

Just a guess here, but I'm thinking that looks more like metastannic acid than gold. There may be some gold in there, but mostly metastannic acid.

Here's what I would do: Incinerate what you have, then soak in warm HCl. Whatever is gold will remain as a solid powder. Many other substances, including metastannic acid will dissolve.

 

[Topher_osAUrus]

Dissolve a bit and test it.

Why did you opt for oxalic to precipitate from an unknown AR solution? Was it a fairly clean solution (no base metals)? From what i have read up on oxalic, it needs to be a very clean solution then it will ppt some beautiful gold if done correctly.

Im not sure if the dirty-ness of the solution could cause gold to look like that when precipitating with oxalic, but, its something to consider.
Personally, on an unknown ar solution i would have went with copperas, cement on copper, or smb (probably in that order, depending on what the ar looked like color wise before i started messing with it). But, that doesn't necessarily mean that is the right way.. Most probably would have cemented I'd imagine...but, always 100 more ways to skin the cat i suppose.

 

[Rmwatson78]