In divination, an anachitis, or anancitis, [1] meaning "stone of necessity" [2] is a stone used to call up spirits from water. [3] It was described as a type of diamond by Martin Ruland the Elder. [1]
The stone was used in classical antiquity by the Magi, being described by Pliny the Elder as one of their "dreadful lies". [4] Its use had fallen out of favour by the Middle Ages. [5]