Unique labels for security or identification purposes, methods of making the labels and uses for the labels are described herein. The label is formed from one or more crystalline materials, optionally in combination with a non-crystalline material, or from a combination of polymers, and has a unique, detectable pattern. In one embodiment, the label is formed from a crystalline material, preferably a metallic material, which naturally contains a unique grain structure, with unique reflective properties. In a preferred embodiment, the label is formed of a metallic material that has been recrystallized to enlarge the size of the grains so that they are visible to the unaided human eye.