Quetelet Rings on a projection TV mirror.

This weekend I brought home 3 rear projection TV's to take apart to get to the Fresnel lenses that are in the screens and while pulling out the mirror that is in the back of the TV, I saw a dust film on it and I happen to see the sun's reflection form colorful Quetelet  rings that curve away from the reflection. These rings were only bright they were very colorful, and well formed