We have grown high quality undoped and n-type GaN crystallites by a novel technique based on direct reaction of gallium metal with ammonia using a two step method. Powders produced by this method consist of at least two differently shaped crystallites; large columnar crystals sized around 10μm and small platelets crystals between 1 and 3μm. The crystallites have a well defined wurtzite structure, with an exceptionally strong near band-edge emission at around 3.342 eV. Yellow luminescence (YL) has been observed in Si-doped and O-doped powders but not in undoped powders grown by this method. © 2005 American Institute of Physics.