(spice) The "spice of spices", the crop for which Arrakis is the unique source. The spice, chiefly noted for its geriatric qualities, is mildly addictive when taken in small quantities, severely addictive when imbibed in qualities above two grams daily per seventy kilos of body weight. (See Ibad, Water of Life, and Pre-spice Mass.) Muad'Dib claimed the spice as a key to his prophetic powers. Guild navigators make similar claims. Its price on the Imperial market has ranged as high as 620,000 solaris the decagram.