Black, extremely high, stationary for duration seen, clear day, no visible lights or flashes, similar in shape to stealth aircraft, no sound.

Black, no sound, no movement for the duration of the sighting.  Credible witnesses. Four retired male co-workers, and one 25 year old female co-worker who looked up to see what it was the others were looking at. It looked like the black stealth plane, but was up extremely high, and stationary, and had me wondering after, why THAT plane would be over this neighbourhood. Then I thought maybe it was a hang-glider, but it wasn't moving.  It was  clear, blue skied, sunny late afternoon. It did not appear to shine like metal, nor did it have any visible lights. It did not change shape or size.  It appeared higher than the highest visible airplane I've seen, and at the same time it's size seemed bigger than an airplane would be at that height.  It has had me wondering since that day what it was that I saw.