I recently dropped a solution of gold and tested the solution after dropping with Stannous and it tested positive .I tried SMB again but got nothing.I added some of the Stannous solution i am useing and it became very black very fast .Is it gold precipitation or Tin?
Is it gold?
- Thread starter brjook
- Start date
Help Support Gold Refining Forum:
tin could replace gold in solution, but can also replace copper, I cannot say the black is gold.
- Joined
- Feb 25, 2007
- Messages
- 8,360
It would be my opinion that the resulting test is gold, but it can be confirmed by placing a small drop of the solution in a spot plate cavity, then a small crystal of ferrous sulfate added. If it's gold, you'll see it precipitate as you watch. Depending on various conditions, it may precipitate as a foil, or as brown powder. I experienced both types of reactions routinely.
To remove doubt when testing with stannous chloride, test in a spot plate. After the reaction, rinse the cavity. If gold was present, there will be a purple stain remaining in the cavity. It can be wiped out with a piece of paper or fabric, or even removed with a drop of AR. To my knowledge, nothing but gold leaves the purple stain.
Harold
To remove doubt when testing with stannous chloride, test in a spot plate. After the reaction, rinse the cavity. If gold was present, there will be a purple stain remaining in the cavity. It can be wiped out with a piece of paper or fabric, or even removed with a drop of AR. To my knowledge, nothing but gold leaves the purple stain.
Harold
Harold_V said:
One of my favorite tricks before i got a spot plate and even still today is to use the cheap plastic disposable spoons that you can get for a $1 a box at Wally World. They wipe off and clean easily for many uses. I love that Purple color.
- Joined
- Feb 25, 2007
- Messages
- 8,360
Great idea, Ralph. Especially for the guy that's just starting out and has yet to acquire the nice little gadets that make testing easier. I'd highly recommend a white plastic spoon to anyone that has no spot plate.
Harold
Harold
A
Anonymous
Guest
Heck I still occasionally use my big plastic stir spoons as a testing surface.I buy them from walmart for $1 for a bag of 5 and they are great.I believe a bought about 5 bags the last time I bought them,that was over a year ago.I still have them all over my shop.The longest one reaches the bottom of my 4000ml erlenmeyer easily.
