Blue disthene is also called cyanite or kyanite. The name disthene is derived from the Greek "this sthénos" (twofold strength, twofold power). This describes a quite unusual property of disthene: It shows - depending on the direction in the crystal - two very strongly deviating hardnesses (so-called hardness anisotropy). Spellings such as Distin, Disthin or Disten have not become established in the retail and wholesale trade.