Abstract: The invention relates to a method for marking an item based on the formation of color centers on a lithium fluoride film. The method provides for the deposition of thin LiF films on the item or on mark supports to be applied to the item and the formation of the color centers by irradiation, thus forming an identification mark. Optionally, the method may provide for the detection of the identification mark and the control of its authenticity. The method may be employed both to guarantee the authenticity of the item and to classify it. The application of the method is particularly advantageous in the field of high value goods and specifically in the field of cultural objects.