Scales of a butterfly
Butterflies are characterized by their scale-covered wings. The coloration of butterfly wings is created by minute scales. These scales are pigmented with melanins that give them blacks and browns, but blues, greens, reds and iridescence are usually created by the micro-structure of the scales. This structural coloration is the result of coherent scattering of light by the photonic crystal nature of the scales The scales are loosely to the wing and come off easily without harming the butterfly.
