Abstract: Security token (20) comprising: a substrate (21) and; an authentication element mounted to the substrate and formed from a solid material containing one or more minerals. Furthermore, a security token authenticator and method comprising: an optical detector arranged to generate a signal in response to an interaction of light with an authentication element within a security token, the authentication element formed from a solid material containing one or more minerals; and a processor configured to: compare the generated signal with a previously obtained signal from the authentication element; and provide an output based on the comparison.

Abstract: Security token (20) comprising: a substrate (21) and; an authentication element mounted to the substrate and formed from a solid material containing one or more minerals. Furthermore, a security token authenticator and method comprising: an optical detector arranged to generate a signal in response to an interaction of light with an authentication element within a security token, the authentication element formed from a solid material containing one or more minerals; and a processor configured to: compare the generated signal with a previously obtained signal from the authentication element; and provide an output based on the comparison.