Present study evaluates the potential of diatomite, a naturally occurring sedimentary rock composed of fossilized diatoms, as a thermoluminescent (TL) dosimetric material. Diatomite samples were exposed to gamma radiation doses ranging from 2 to 20 Gy. The TL glow curve revealed a single prominent peak within 180–260 °C, indicating a well-defined and stable trapping level. The dose response showed excellent linearity (R2 = 0.989), and the material demonstrated good sensitivity at 2 Gy with high reproducibility (standard deviation < 4 %). A fading study over 35 days confirmed that the TL signal remained stable at room temperature. Kinetic parameters, including activation energy (E), frequency factor (s), order of kinetics (b), and trap lifetime (τ), were determined using the peak shape method, providing insight into the trapping and recombination processes. Elemental analysis via energy-dispersive X-ray spectroscopy (EDX) identified O, Mg, Ca, and C, with an effective atomic number (Zeff) of 10.3, close to that of human bone. These findings demonstrate that diatomite powder possesses favorable dosimetric properties under gamma irradiation, making it a promising low-cost, stable, and tissue-equivalent natural material for thermoluminescence dosimetry applications.