Gak's Fotothing

Less symmetric crystal structures, more distorted arrangements of molecules within a crystal that gives it its form, produce refractive indices in the crystal that are different in different directions, depending on the way light travels in the crystal. Different refractive indices experienced by each of the split components of light that passes through such a crystal will cause interference colors when the components are recombined in the analyzer filter.

This is a virtual double exposure that I call a synthetic aperture composite image.