Elliptical halo 3-29-2013

On Good Friday which happened to be my birthday I saw some AC clouds coming in and precipitating into a layer of crystals and saw an elliptical glow around the sun. It was after I put on my sunglasses I realized an elliptical halo had been in progress. The halo came and went and sometimes it would do that expand and shrink and at one stage the top part of the ellipse had straight angles sides making it look diamond like in shape.