Fuzzy, hazy triangular object observed for 5 minutes blending into night sky. Object started as V-shaped triangle then transformed to wing-like appearance before vanishing. Two witnesses observed craft gliding at bird-flight height (1,000-2,000 feet) at steady 20-25 mph speed. Dark gray coloring matched night sky for camouflage effect. Size estimated at 50-60 meters with aura or haze surrounding object.