Step 1
To protect the piece you want to test as much as possible from testing damage, start by rubbing or scratching the item you want to test directly against the surface of the testing stone. As you do this, you will notice that the metal leaves a mark on the testing stone. Press firmly on the testing stone to leave a thick and visible deposit that you can test accurately. The mark should be about 1″ to 1-1/2″ inches long.
Step 2
Place a drop of the 22 karat gold testing acid on the stone across the streak you made with the metal. As soon as the acid hits the testing stone and marks, be prepared to observe the changes.
Be aware that you can use either 18 or 22 karat gold testing acid to test for palladium, but we recommend you use 22 karat testing acid because it will give you the clearest results.
Step 3
Observe the reaction of the streak to the acid. If the metal has palladium content, it will very slowly turn a yellowish green color. If there is no palladium content, the streak will fade completely away.
