Providing permanent identification markings on gemstones - using proton bombardment to transform the crystal lattice

摘要

Identification markings are provided in the interior of a gemstone crystal lattice by patterned proton bombardment. The gemstone is cooled during irradiation to confine the resulting lattice transformation to the desired area and depth. In a pref. embodiment the gemstone is diamond and the bombardment produces localised transformation to amorphous C or graphite; patterned markings are obtd. using a proton mask of e.g. metal. Permanent, irreversible identification markings are produced which may be sufficiently small to be detectable only with a microscope; the quality and properties of the stone are unaffected.