I observed a stationary, dull metallic colored disk for approximately 25 seconds before it disappeared.

I was looking at clouds when I noticed a stationary object in the Western sky. It was dull metallic in color and made no sound. It was disk shaped with the exception of a half sphere attached to the bottom of the object. I'm guessing that it was 500 to 800ft in altitude. I took a picture using my cellphone camera. After I took the picture I checked it and when I looked at the sky again the object was gone. The entire sighting lasted about 25 seconds.