Extremely fast moving, dimly lit, triangular shaped object in sky.

I was in my backyard with my boyfriend looking at the stars. I saw what I thought was a satellite and started to say so but it was moving way way too fast. He looked up and saw it as well. There were no trails or lights just an extremely fast moving object in the night sky traveling we believe from North to South. It was moving as fast as a shooting star, never stopped moving and continued across the upper western horizon until we could no longer see it. We tried to think of anything it could have been but it was moving so so fast, was silent and had no lights or flashes making it somewhat difficult to see. What slight glow(if any) or silhouette of the object we could see looked to be triangular or possibly diamond shaped. Too fast to be a satellite, too quiet and unlit to be a lower flying jet and too high up and fast to be a bird. Possibly some new technology stealth aircraft? That's what we're telling ourselves.