Observed a bright blue glowing object approx 30 degrees above, to start, of horizon. Started video taping as soon as I noticed while leaving my office walking to my car. Object began to pulse and I was facing due north at the time. Object began to descend slow then move to the east. Object then hovered and appeared to rapidly change form to a chevron type form and darted west. Object continued strange east to west movement rapidly accelerating at some differing points. Including darting up and down. Continued to video and observe for approx 5-10 mins. Object was very difficult to videotape for some reason even at full zoom on iPhone. Actually even got in car and drove a little further north to see if video would be better if I got around this tree. Then tried to get more video. I had to move car and leave because I was actually causing a rush hour traffic issue. I live and work under the Dulles flight path and there were multiple airliners in the sky also. I am also a trained observer and have knowledge of most foreign and domestic aircraft including SOAR craft and lighter then air. This was neither. My inclination was a personal uav that was a hoax, or a govt model. But in this area that is a very risky hoax! But this did not strike me as a drone and I pretty familiar w gov models also!I ended up driving away to go home and lost sight of the object. Fiance and I discussed what we saw and I placed a call to FFX Co Emergecy Ops Center to see if anyone else had sen or reported. Dispatcher checked in w other units in area and at that said no other reports as of yet and they confirmed they had no helicopters in area either. They then referred me to non emerg FAA number but instead we are sending to you. We have approx 10 minutes total of video that fiancé and I trying to figure which video to send and how to upload. Thank you for your time in advance.