Why is the conductivity value of my silver coin lower than the target value?

In some silver coins (999 fineness), the last thousandth contains “impurities” such as iron or nickel. A classic example of this is the Krugerrand silver coin (conductivity value: approx. 55–60 MS/m). As a result, the coin’s conductivity value on the GoldScreenSensor often falls into the lower range, even though it is genuine. Additional testing methods will confirm the coin’s authenticity. The same effect can also be observed with other items, such as the “Tokelau 4th Edition Terra | Earth 2021” silver coin.