Electron paramagnetic resonance dosimetry and dating potential of whewellite (calcium oxalate monohydrate)

We use electron paramagnetic resonance (EPR) to demonstrate the presence of radiation-induced paramagnetic species in synthetic whewellite (CaC2O4·H2O), with the primary EPR signal at g=2.0042. The radiosensitive EPR signal has a lifetime of at least 1 year. Freshly synthesized whewellite also displays a paramagnetic signal that increases in intensity upon exposure to fluorescent light. Although the widespread occurrence of natural whewellite suggests applications in geological or archaeological dating, no corresponding radiosensitive EPR signal has been identified in samples of natural whewellite.