Mirror Gazing

"Mirror gazing is one of the many forms of scrying: divination by looking into a reflective surface. The mirror is used in much the same way as a crystal ball, with the deviner seeing images from the past, present, and future. All types of mirrors have been used, including those with polished metal faces, glass, crystal, and obsidian. The mirror may or may not be enclosed in a frame, and if it is, it is usually engraved or marked in some way with sigils to help amplify the images given.Many diviners say that a black or concave mirror is far superior to any other..."

-The Element Encyclopedia of the Psychic World