Is a yellow solution from nitric a specific indication?

[Ragnor]

I conducted a test on a 1 gram ore sample today in a 25ml beaker using just enough 68%nitric to cover the sample and further diluted that solution with an equal volume of water. A nice slow dissolution (safety conscious).

Again I get a yellow solution which turns to a rusty orange at higher concentrations.

I have started doing some reading, but have not run across the answers yet as to what colors mean what metals.

Is the yellow reaction specific to a certain metal? That last batch that started off like this did test positive for platinum (stannous test) after it was fully reacted.

 

[4metals]

Unfortunately simply color change rarely can pin down a specific metal, especially yellow.

 

[Ragnor]

Thank you for the response.


I'm going to add this image. Can anyone confirm that this is a positive result for platinum using stannous test?
This is the result from the solution I made made today. I have not yet added any hcl or salt.

Also I was wrong, it's a 50ml beaker

 

[g_axelsson]

Check this thread.
http://goldrefiningforum.com/phpBB3/viewtopic.php?f=41&t=5271&p=45030#p45030

Göran

 

[Lino1406]

Platinum will not dissolve in nitric acid

 

[Platdigger]

Except, with enough silver.

 

[Ragnor]

Ag, Au, Pt is a very high probability for this material.



"I don't know Herman, that looks like pyrite to me", I said. "That's the gold!" the old man snapped back at me angrily.....

 

[Ragnor]

This is the result after adding 1/4 tsp. of table salt to the mix.