In the spoon, try diluting 1 drop with 3 or 4 drops of distilled water. Then add 1 drop of stannous chloride and see what you get. Sometimes you get better results by diluting highly concentrated samples. It takes very little gold to show up.
By the way, porcelain spot plates are cheap and better than spoons.
http://www.hometrainingtools.com/porcelain-spot-plate
Porcelain spot plates are also very handy for dissolving and testing very small quantities of metals (or ores, concentrates, etc). In the field, I used them to test for various PM brazes on stators on jet engines. I filed off some of the braze (file fairly deep) with a very small triangular file onto a clean sheet of paper. I transferred a few filings to a spot plate and added a drop of nitric and 4 drops of HCl. When dissolved, I tested (for gold/nickel braze) with a drop of stannous chloride. I used other solutions to pinpoint the Ag/Cu and Ag/Cu/Pd brazes. To speed the dissolving, you can put the spot plate on a warm hot plate or a sheet of steel that's been sitting in the summer sun. You can also heat a spot using a cigarette lighter or small torch underneath that spot. Ms. Hoke talks about the hotplate thing in her Testing book (free download). She also uses an abrasive to roughen the spots for rubbing PM objects, like on a touchstone. Reading this book will convince you of the value of spot plates.
They also work great for keeping the chunks of lead in proper order when doing fire assay cupellations - I numbered the spots 1 thru 12.
I assume these cheap spot plates (probably Chinese) will hold up to the heat and chemicals. I've always used the Coors brand but they are now $27 and up. There are dark blue ones, black ones and clear Pyrex ones that I haven't tried. I've always thought the black ones might be better for light colored things like silver chloride and DMG Pd. Coor's original black porcelain ones contained a uranium compound, I think.
By the way, porcelain spot plates are cheap and better than spoons.
http://www.hometrainingtools.com/porcelain-spot-plate
Porcelain spot plates are also very handy for dissolving and testing very small quantities of metals (or ores, concentrates, etc). In the field, I used them to test for various PM brazes on stators on jet engines. I filed off some of the braze (file fairly deep) with a very small triangular file onto a clean sheet of paper. I transferred a few filings to a spot plate and added a drop of nitric and 4 drops of HCl. When dissolved, I tested (for gold/nickel braze) with a drop of stannous chloride. I used other solutions to pinpoint the Ag/Cu and Ag/Cu/Pd brazes. To speed the dissolving, you can put the spot plate on a warm hot plate or a sheet of steel that's been sitting in the summer sun. You can also heat a spot using a cigarette lighter or small torch underneath that spot. Ms. Hoke talks about the hotplate thing in her Testing book (free download). She also uses an abrasive to roughen the spots for rubbing PM objects, like on a touchstone. Reading this book will convince you of the value of spot plates.
They also work great for keeping the chunks of lead in proper order when doing fire assay cupellations - I numbered the spots 1 thru 12.
I assume these cheap spot plates (probably Chinese) will hold up to the heat and chemicals. I've always used the Coors brand but they are now $27 and up. There are dark blue ones, black ones and clear Pyrex ones that I haven't tried. I've always thought the black ones might be better for light colored things like silver chloride and DMG Pd. Coor's original black porcelain ones contained a uranium compound, I think.
