Much like the basic yellow gold streak test, with the white gold streak test you will rub the unknown metal against the testing stone and then apply acid to the stone to see how it reacts. The two major differences is that you will not have a white gold needle streak to compare the unknown metal’s reaction to, and that since most white gold has some plating to enhance the silver tones of the metal you may not get an accurate result right away with this method.
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.
Place a drop of the 22 karat acid on the stone where the two gold marks are. As soon as the acid hits the testing stone and the marks, watch the reaction to determine what kind of metal you are dealing with.
- If the white metal you are testing is 18 karat white gold, the scratch mark will turn a light bronze color in the first three minutes after applying the acid.
- If the white metal you are testing is 14 karat white gold, the scratch mark on the stone will disappear in about 15 seconds.
- If the metal is actually stainless steel and not white gold at all, the streak will remain unchanged on the stone.