Dislocations in high quality Heat-Exchanger Method (HEM) produced sapphire were analyzed with the white beam large area transmission synchrotron X-ray topography technique. After analysis the dislocations for different Laue spots, i.e. different diffraction vectors, in one recorded film, three kinds of dislocations, i.e. screw, edge and mixed dislocations were identified in the studied HEM sapphire, but most are mixed type, whose Burgers vectors belong to the two groups of <2 (1) over bar(1) over bar0> and <1 0(1) over bar 0 >. (C) 2003 Elsevier Science B.V. All rights reserved.