Strange white craft appears to go out of focus as if trying to engage faulty cloaking devise....My co-worker and i were speaking to our supervisr, truck to truck, when our supervisor drew our attention to what appeared to be ice crystals falling from the sky in a small area, they were unusual as the were large but, obviuosly light. We dismissed this as wind blown ice. My supervisor drove off and we began to as well. My partner and I then noticed an object in the southeast sky that was in the forground with 2 jets in the background both showing contrails. The object appeared to be oval and very white or was reflecting the sun to a high degree. It looked to us as if it was traveling away from us as it was getting smaller with no side to side deviation from its course. We have both seen alot of aircraft both jets and props, and this was not a famlier "look" to the object. We were both watching it for about 2 mins when suddenly it appeared to go out of focus as if it was caught in the shimmer over heat sources. We both said at the same time "did you see that!?" The object then began to glow very brightly for 30 secs then faded again and rapidly dwindled away going up and showing no contrail. My partner said he thought there was a glow around it but i did not see it except when it was bright. We both watched it till it dissapeared in the distance. WE work for a parks dept and spend aalot of time outside and there is a military airbase very close to us and are used to various air craft in our skies