The mark comprises a black circle having two inwardly-directed, slightly offset, asymmetric white crescents having therebetween an entirely off-center small white circle with surrounding halo, which halo has a diameter half that of the black circle and is in the form of a series of approximately eighteen concentric equi-thick circular bands (annular rings) with each band having the appearance of being separated from the next by a darker narrow ring and which bands shade from a light gray adjacent the white circle to increasingly darker grays until the outer bands to fade into the black of the larger design (before reaching either the center or outer edge of the overall black circle).