Scrying

Scrying is a psychic practice that involves seeing things supernaturally in a medium for purposes of divination or prediction. Scrying has been used in many cultures as a means of divining the past, present, or future. Depending on the culture and practice, the visions that come when one gazes into the media are thought to come from God, the psychic mind or the subconscious.
It is also known as also known as crystal ball gazing, crystal seeing, seeing, or peeping.
The media used are most commonly reflective, translucent, or luminescent substances such as crystals, stones, glass, mirrors, water, fire or smoke. Scrying is also performed using tea leaves or coffee in a cup.
Nostradamus is believed to have employed an obsidian mirror as a scrying aid.