The present invention is an imprint device for imprinting a unique identification mark on a surface of an object with imprinting particles of different sizes that increase uniqueness and without the need for electric power. The imprint device includes a vertical member, a hammer member, a trigger assembly, a charging unit, a barrel and at least one pocket. In the operative configuration, a trigger of trigger assembly is activated such that hammer member impacts a cartridge filled with at least one munition of imprinting particles and releases imprinting particles. The imprinting particles travel through the barrel where acceleration is increased and impact on surface is made to form microcraters and unique identification marks. The imprinting particles can be of same size, material and shape or they can be of different sizes, material and shapes or the combination thereof for increasing uniqueness.