UFO Sighting in Sparks, Nevada on July 2nd 2015 – seen rectangular cube shaped, bright silver, craft fly overhead, watched 5min until it went behind stormclouds

I was at work at a retail store, just me and my coworker in there at the time. I was looked out the window seeing how far away the thunderstorm was. The windows in my store Are two story high and facing East. It was almost 7pm When I seen a perfectly rectangular, sharp 90�� edges, very shiny silver craft, about 8in in length, 5in in width, 5in in hight from my point of view. Fly over my store heading towards the area of Pyramid lake, N.E. direction. It was below the scarred thunderstorm clouds, the wind and storm was going N.W. and had mostly already passed and was about 5 miles away. Me and my coworker watched the thing travel in a straight line for about 4 or 5 min untill it was the size of grain of rice when it went into clouds and we lost sight of it. The sides of it were extremely shiny but looked like they were textured, there were absolutely no Wings, lights or anything normal, cuboid shaped silver flying box. It didnt move around in the wind, stayed on a straight path. We were inside so we didn't hear any noise. We were shaken up afterwards. Fallon air base is not far and we regularly have military flying overhead. This was NOT anything I have ever seen before in my 41 years.