The formation of histologically mature bone within the intracranial compartment is an exceptionally rare phenomenon. Although intracranial calcifications are frequently encountered in clinical practice, true ossification culminating in the development of mature bone tissue remains poorly characterized. Herein, we report three cases of female patients presenting with intra- and extra-axial cranial masses, all histologically confirmed to comprise mature bone. We describe the associated radiologic features, surgical challenges, and histopathological findings. Furthermore, we propose a novel pathogenetic hypothesis implicating the intraoperative dispersion of bone dust as a potential etiologic factor in iatrogenic ossification. Our findings highlight the importance of surgical vigilance and meticulous intraoperative technique to mitigate this rare but avoidable complication.