Patent ID: 8705805

Claim:
A method of identifying and authenticating portable tokens, the method comprising the steps of: (a) directing light from a polychromatic, or monochromatic, linear-polarized light source toward an essentially transparent portable token including a planar rock section of naturally-occurring rock of the Earth's crust of less than 250 micrometers in its least dimension and being in part or in whole transmissive of light rays in its least dimension; (b) using a means of generating an image to form an image from that light which may be transmitted by the planar rock section through its least dimension; (c) using a means of recording images, being either a photographic plate or an electronic image-recorder, to capture the light rays of the image and to record an image; (d) storing the image data into one or more storage repositories for recorded reference images, as a reference to which later images recorded by the method may be compared; (e) selecting a position in any particular mineral grain that exhibits a variation in luminance between images recorded with different angular values between the polarization-axis of the linear-polarized light source and a predetermined axis that is orthogonal to the least dimension of the planar rock section; (f) allowing the passage of any amount of time, during which time the portable token may, or may not, be removed from the means of generating an image apparatus; (g) the repeating of steps (a), (b) and (c) after the said passage of time, wherein the essentially transparent portable token is now subject to inquiry; (h) storing the image data into one or more storage repositories of data of recorded images, as image data to be subjected to inquiry by a comparison process; (i) comparing those recorded image data of the planar rock section that were recorded as a reference with those that were recorded for inquiry, by a comparison process, wherein the comparison process may use a computer-processor and memory; (j) deciding upon the identity and authenticity of the portable token based upon a matching correspondence, or lack thereof, between the reference image data and the image data of the subject of inquiry; (k) indicating, as a binary logic output, the decision as to whether or not the planar rock section in the portable token is authentic.