Dichroic Glass Earrings, The dielectric coating that produces all the interesting colors is not the glass at all, but a stack of very thin layers of metal oxides, such as titanium, silicon and magnesium. This stack has a total thickness of three to five millionths of an inch. The Layers produce an interference filter, creating the varied and unique color characteristics we see. Since the filter is so thin, it has mechanical integrity of its own, and must be supported on a stable substrate. Glass is the ideal candidate for this. Combined with the glass, the Dichroic coatings create an interference effect transmitting wavelengths of light. The transmitted color is different from the reflected color, and viewing from a 45 degree angle produces a third color. The results are pure, saturated single wavelengths of light, that appear to originate from within the piece.