The pineal gland is a neuroendocrine transducer secreting melatonin, responsible for the physiological circadian rhythm control. A new form of biomineralization has been studied in the human pineal gland. It consists of small crystals that are less than 20 µm in length. These crystals could be responsible for an electromechanical biological transduction mechanism in the pineal gland due to their structure and piezoelectric properties. Using scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS), we identified crystals morphology and showed that they only contain calcium, carbon and oxygen elements. Furthermore, the selected-area electron diffraction (SAED) and near-infrared Raman spectroscopy established that the crystals are calcite. We will now focus on the physiological effect of microcrystals in pinealocyte cell culture under Radio-Frequency Electromagnetic-Fields (RF-EMF).