(Edit... apologies for the rambling post. This is all pretty new to me and I'm having difficulty understanding test results that are less than absolutely conclusive one way or the other.)
I'd like to use stannous chloride testing against multiple small samples of crushed rock to identify potential sources of precious metals. Rational here is that this approach would be faster than crushing larger amounts of rock followed by panning. Has anyone had success with this approach? Are there reasons that this might not be a good idea?
Below is my initial attempt.
1. Crushed samples
2. Covered samples in AR for an hour with occasional stirring
3. Neutralized nitric with urea
4. Did not filter AR since samples are for testing only
5. Dipped Qtip into AR, one per sample
6. Placed Qtips on paper towel
7. Poured stannous chloride onto each Qtip
In the pic below, sample 4 (farthest right) showed a yellow/orange color after application of stannous chloride. Pretty much same color as Qtip after dipping it into sample but before stannous chloride. Perhaps, a bit more yellow. Sample 2 Qtip lost all color after application of stannous chloride but then developed a very slight yellow color. All other samples' Qtips lost all color after application of stannous chloride.
I've read that a yellow or orange response is consistent with Pt. I'm wondering if the results are so subtle that I should consider all tests to be negative or I should retest sample 2 and sample 4 with filtered AR to rule out possibility that some particulate matter on Qtip is responsible for yellow color instead of dissolved Pt.
I'd like to use stannous chloride testing against multiple small samples of crushed rock to identify potential sources of precious metals. Rational here is that this approach would be faster than crushing larger amounts of rock followed by panning. Has anyone had success with this approach? Are there reasons that this might not be a good idea?
Below is my initial attempt.
1. Crushed samples
2. Covered samples in AR for an hour with occasional stirring
3. Neutralized nitric with urea
4. Did not filter AR since samples are for testing only
5. Dipped Qtip into AR, one per sample
6. Placed Qtips on paper towel
7. Poured stannous chloride onto each Qtip
In the pic below, sample 4 (farthest right) showed a yellow/orange color after application of stannous chloride. Pretty much same color as Qtip after dipping it into sample but before stannous chloride. Perhaps, a bit more yellow. Sample 2 Qtip lost all color after application of stannous chloride but then developed a very slight yellow color. All other samples' Qtips lost all color after application of stannous chloride.
I've read that a yellow or orange response is consistent with Pt. I'm wondering if the results are so subtle that I should consider all tests to be negative or I should retest sample 2 and sample 4 with filtered AR to rule out possibility that some particulate matter on Qtip is responsible for yellow color instead of dissolved Pt.
