Halomancy

Halomancy (from the Greek: ἅλς, háls ["salt, sea"] + μαντεία, manteia, ["divination, soothsaying"]), or alomancy, is any method of divination conducted by use of salt, be it the interpretation of salt crystals cast into the air or a fire, or the patterns of salt crystals left in evaporated salinated water.

Reading

• Timayens, T. T. (1887), "Alomancy", A History of the Art of Magic: Containing Anecdotes, Explanation of Tricks and a Sketch of the Life of Alexander Hermann, New York: J.J. Little, p. 26, https://archive.org/details/historyofartofma00tima/page/26/mode/2up 
  

  From the Greek als, meaning salt. This is divination by salt, which the ancients regarded as sacred. It is well known that salt was one of the most important ingredients in ancient Greek sacrifices; in fact, to omit placing a salt-cellar near the spot where the sacrifice was to take place was deemed the forerunner of great misfortunes. Among early Christians salt was regarded as the symbol of wisdom, and many people still regard it as a misfortune to spill salt accidentally upon the table.