Bismuth　ions,　as　excellent　non-rare-earth　activators　for　luminescent　materials,　possess　characteristic　excitation　in　the　near　ultraviolet　(n-UV)　region　rather　than　in　the　visible　region　and　could　avoid　reabsorption　as　compared　to　traditional　rare-earth　(e.g.,　Eu2+,　Ce3+)　phosphors.　In　this　work,　a　series　of　apatite-type　NaGd9(SiO4)6O2:　xBi3+　(NGSO)　phosphors　with　a　hexagonal　crystal　system　were　synthesized　through　high-temperature　solid-solid　reactions.　They　showed　intense　n-UV　absorption　and　cyan　emission　of　Bi3+　ions.　The　optimal　Bi3+　doping　concentration　was　0.02.　Further,　there　were　two　types　of　Bi3+　ions　that　provided　seven-　and　nine-coordination　in　NGSO:　xBi3+　phosphors,　resulting　in　two　luminescence　centers　at　462　and　558　nm,　respectively.　Bi3+　(I)　ions　were　dominant　for　the　emission　at　558　nm　excited　at　a　wavelength　of　340　nm,　and　Bi3+　(II)　ions　governed　the　luminescence　at　462　nm　excitation　at　370　nm;　energy　transfer　occurred　from　Bi3+　(I)　to　Bi3+　(II)　ions.　Finally,　good　thermal　stability　with　activation　energy　(Ea)　of　0.296　eV　was　demonstrated.　These　findings　exhibit　the　potential　application　of　NGSO:　0.02Bi3+　phosphors　as　cyan　phosphors　in　n-UV　white　light-emitting　diodes.