Dark, Black Triangle Craft

It was a clear night, a friend and I were standing in my backyard when I looked up into the sky and saw a large floating dark triangle moving slowly across the sky from west to east.  Object made no sound and no lights were present.  We could make out the shape as it blotted out the stars behind it.  We both just stood there and watched in disbelief as it floated off and was obscured by trees.