Abstract: A coin comprising a metallic disc separated from a concentric annular metallic ring by a concentric intervening layer. The metallic disc has a first electrical conductivity and the annular metallic ring has a second electrical conductivity. This intervening layer comprises a transparent dielectric material that connects the metallic disc to the annular metallic ring. The intervening layer has a width to provide a separation of inductive signatures of the metallic disc and the annular metallic ring. The width is based on an electrical conductivity ratio of the first electrical conductivity to the second electrical conductivity and is further based on a geometry of the coin. In some embodiments, the intervening layer comprises a transparent polymer including additives, such as a UV stabilizer or a fluorescent component.

Abstract: A coin blank provides an inner portion and at least one outer portion surrounding the inner portion. A dielectric isolation layer is arranged between the inner portion and the outer portion and connects the inner portion and the outer portion in a force-locking manner. The isolation layer is transparent in a first wavelength range and may be based on a transparent polymer. The isolation layer may contain additives absorbing and/or reflecting light in a second wavelength range.