On that thought, everything in contact with your body capable of vibrating would (and probably does) act as a resonator. Some materials better, others less. I suspect the tricky part would be to pin down one frequency of the body, because it is made up of so many overlapping, amplifying and extinguishing frequencies. But basically, it should vibrate in a frequency similar to your bodies overall output signal ... or the locally strongest signal depending on where you attach the quartz on your body.
edit: transfer of body heat is a perfect example.
edit: transfer of body heat is a perfect example.
_ - Third Stone From The Sun - _
