# Stannous chloride tests



## Adam7062 (May 3, 2010)

Hi, my name is Adam. I'm new on the forum. After reading the book of Hoke and Handbook vol 1 I noticed that there is some inconsistent information regarding colors resulting from the stannous chloride tests.

HOOK:
USING STANNOUS CHLORIDE WITH PLATINUM
Take the spot plate and drop one drop of the standard platinum
solution into a cavity. Notice the pale yellow color. This deep yellow
color with Solution A is a characteristic of platinum and iridium.
WITH GOLD
Note the first intense dark color, deep purple or black.
This is characteristic of gold. After it stands a few minutes, notice
the purple stain on the white porcelain.
WITH PALLADIUM
... you see a deep yellow, not unlike the effect
produced by platinum. After some minutes the yellow turns bluegreen.
This blue-green color is characteristic of palladium.

Handbook 1:

Purple/Black color is Gold in solution, the darker the spot the more Gold.
Yellow/Brown color is Palladium in solution, the darker the spot the more Palladium.
Light/Dark Rose color is Platinum in solution, the darker the spot the more Platinum.

Which tests colour is correct?

Thanks for clarifications.
Adam


----------



## Barren Realms 007 (May 3, 2010)

Reading your test colors comes with experience.


----------



## Harold_V (May 4, 2010)

Adam7062 said:


> Which tests colour is correct?


My experiences lead me to believe that platinum will respond with a color that ranges from a very light orange through a dark brown. The variations appear to be due to concentration level of platinum, with less being very light in color, and more being very dark. Also, do not discount the age of the testing solution, which tends to fall off as it ages, and will display much weaker colors. 

I do not recall, ever, getting a response that could be classified as dark rose, and I recovered roughly 75 troy ounces of platinum in my years in the lab. 

Palladium, as I have stated previously, is the chameleon of the metals. It will manifest itself in several ways, due to concentration and age of the stannous chloride solution involved in the test. It is best to have DMG available, plus some crystals of ferrous sulfate, when testing mixed solutions. By using a crystal of ferrous sulfate, you can eliminate all traces of gold chloride, which then allows the resulting stannous chloride test to expose the presence of either platinum or palladium. In complex testing, you may even test with DMG before stannous chloride, to isolate traces of platinum. It all comes with experience. 

Hope this helps.

Harold


----------



## Oz (May 4, 2010)

For a friend wanting some pictures of different concentrations of Pt in solution with AR and the reciprocal stannic indications I digested some rather pure Pt. I have never gotten anything but a darker orange from the stannic tests with higher concentrations even after they had dried. I would suspect a slight contamination of gold or Pd if you start getting a brown.

Harold has more experience than I do though, perhaps he will reply if the contaminates I suggested were possibly present in the platinum he was testing.

I have never seen a dark rose with Pt either.



Oops, I am going to leave what I wrote above but I just realized that the dark rose might have been in reference to Pt in solution, not a stannic test (a huge difference that needs clarification). Having said that, yes, it can be a dark rose in solution. Here is a picture of Pt at 80 grams per liter after triple boiling to remove nitric.


----------



## Lou (May 4, 2010)

Platinum will go dark red with stannous.


----------

