The invention relates to a passive medical identification device 1 to be used for identifying a medical tool such as, for example, a surgical instrument, if the medical tool is equipped with the identification device. The identification device comprises a casing 2, a magnetic object 3 arranged within the casing such that it is rotatable out of an equilibrium orientation by an external magnetic torque, and a restoring torque provider 4 such as, for example, a further magnetic object providing a restoring torque forcing the magnetic object back into the equilibrium orientation. The magnetic object 3 rotationally oscillates upon excitation by an external magnetic torque, thereby generating a response magnetic signal which is transduced into an induction signal that can provide a fingerprint specific for the respective identification device. Accordingly, the identity of the identification device and hence of the medical tool equipped with the identification device can be determined based on the induction signal.