Calcium carbonate stones in the utricle and saccule of the vestibular system are pretty interesting (I think they could be what you're looking for). They are part of the response to acceleration; if they're messed up, you can get vertigo.
Calcium carbonate stones in the utricle and saccule of the vestibular system are pretty interesting (I think they could be what you're looking for). They are part of the response to acceleration; if they're messed up, you can get vertigo.