A fictional type of crystal used by science fiction fantasy author, Terry Brooks. These crystals are used to convert light energy gathered by special sails in order to propel flying ships resembling conventional sailing ships. These flying ships appear in trilogies, The Voyage of the Jerle Shannara and The High Druid of Shannara.
"... the jib was used by airships to absorb a wider swath of ambient light that could be converted to energy by the diapson crystals that powered the ship", (Jarka Ruus by Terry Brooks, 1st hardcover edition page 212-213)
by Al Erickson January 23, 2007