This research work explores the crystallographic properties of synthesized F^– and Fe³⁺ doped hydroxyapatites (HAPs) as a function of dopant ion concentration coupled with thermal treatment. Doped HAPs were synthesized using eggshell as the prime source of Ca while X-ray diffraction technique enabled the investigation of desired crystallographic parameters. Observed results attributed that fluoride substitution facilitated the formation of bi-phasic HAP while iron substitution resulted in apatite with single phase. Crystallographic information revealed that gradual increase of F^– ion concentration expedited percentage increase in crystallite size, fraction of crystallinity and crystallinity index of fluoride doped hydroxyapatite (F-HAP) and thus microstrain, dislocation density reduced. Nevertheless, in case of iron doped apatite the scenario was in reverse direction. For both categories of doped HAPs enhanced crystallinity was achieved by thermal treatment. This is because higher temperature accelerated the small sized grains to be in amalgamated form producing larger grains.