IMPORTANT - HOW TO USE Take off probe COVER Touch PROBE with your finger make sure it is sharp. Touch STONE WITH PROBE with LIGHT PRESSURE the point of the probe on the top of the stone that you are testing. Give it a 1/4 turn to the left and a 1/4 turn back to the right. DO NOT RUN THE TIP OF TESTER PROBE ACROSS THE STONE OR YOU COULD DAMAGE THE PROBE POINT. Look through your loupe. If the stone is fake you will leave a small dimple or micro dot on the stone you tester. If the stone is real there will be no mark or dot on a real diamond. It never lies. You may buy or Pawn the stone. If you are not sure of yourself, repeat this process. 100% Foolproof. 321-863-7207