TESTING FOR SILVER
Scratch the piece to be tested over the surface of the black stone provided, press well so as to leave a LARGE AND THICK visible deposit, preferably a line of one to one-half inches long.
Transfer a drop of the silver solution to the scratch made, The color reaction of the solution with the metal scratch will be as follows: (Take into consideration that the background of the test stone is black).
NOTE: With the silver solution, it is possible to test directly on the piece being tested, however, the solution will dull the polishing of the piece, and leave a mark where the acid was placed.