I found this interesting text on one website, issuing field test for gold in the ore. It just state this:
"A test known as Darton's is believed to be a valuable means of detecting minute quantities of gold in rocks, ore tailings, etc.
"Small parts are chipped from all the sides of a mass of rock, amounting in all to about | ounce. This is powdered in a steel mortar and well mixed. About half is placed in a capacious test tube, and then the tube is partly filled with a solution made by dissolving 20 gr. of iodine and 30 gr. of iodide of potassium, in about 10 ounces water. The mixture thus formed is shaken and warmed. After all particles have subsided, dip a piece of fine White filter paper in it; allow it to remain for a moment ; then let it drain, and dry it over the spirit lamp. It is next placed upon a piece of platinum foil held in a pincers, and heated to redness over the flame. The paper is speedily consumed; and after again heating to burn off all carbon, it is allowed to cool and is then examined. If at all purple, gold is present in the ore, and the relative amount may be approximately deduced. This method takes little time, and is trustworthy."
"
My understanding is that iodine/iodide should dissolve gold into the solution from crushed ore. Then, potassium tetraiodoaurate is in solution. This is soaked into the filter paper, which is then heated - I assume iodine will evaporate, leaving just non-volatile residue.
Then, the paper is essentially burned on platinum foil (platinum just for it´s corrosion resistance, or it has any other deeper meaning ?) and violet residue should indicate gold...
I can imagine that working, but at the same time, I have doubts about actual sensitivity.
Is this of any use in real life ? Do anyone has experience with it ?
Link to the page where I found this:
http://nevada-outback-gems.com/Prospecting_Basics/gold_field_test.htm
"A test known as Darton's is believed to be a valuable means of detecting minute quantities of gold in rocks, ore tailings, etc.
"Small parts are chipped from all the sides of a mass of rock, amounting in all to about | ounce. This is powdered in a steel mortar and well mixed. About half is placed in a capacious test tube, and then the tube is partly filled with a solution made by dissolving 20 gr. of iodine and 30 gr. of iodide of potassium, in about 10 ounces water. The mixture thus formed is shaken and warmed. After all particles have subsided, dip a piece of fine White filter paper in it; allow it to remain for a moment ; then let it drain, and dry it over the spirit lamp. It is next placed upon a piece of platinum foil held in a pincers, and heated to redness over the flame. The paper is speedily consumed; and after again heating to burn off all carbon, it is allowed to cool and is then examined. If at all purple, gold is present in the ore, and the relative amount may be approximately deduced. This method takes little time, and is trustworthy."
"
My understanding is that iodine/iodide should dissolve gold into the solution from crushed ore. Then, potassium tetraiodoaurate is in solution. This is soaked into the filter paper, which is then heated - I assume iodine will evaporate, leaving just non-volatile residue.
Then, the paper is essentially burned on platinum foil (platinum just for it´s corrosion resistance, or it has any other deeper meaning ?) and violet residue should indicate gold...
I can imagine that working, but at the same time, I have doubts about actual sensitivity.
Is this of any use in real life ? Do anyone has experience with it ?
Link to the page where I found this:
http://nevada-outback-gems.com/Prospecting_Basics/gold_field_test.htm