Imagine a
bar of soap made to resemble a coin (a large novelty soap coin
replica). You put it on your sink as a decorative item in the guest bath. But you run out of Irish
Spring, so you use your fancy coin soap for a few
baths. Imagine what the
bar of soap would look like then.
Now take another look at the coin above.
This is one way of detecting
cast fakes. The
soapy look on this one is particularly evident.