Iridescent Clouds Posted on September 3, 2013 by Sheila Creighton Posted in Sky Views Tagged clouds, colors, colours, copyright, diffraction, phenomenon, photography, sun 12 Comments I saw this strange sky view (not a Sundog) and had to check out what it was. Wikipedia says, “Iridescent clouds are a diffraction phenomenon caused by small water droplets or small ice crystals individually scattering light.” © Sheila Creighton 2013