FMF - Friends of Minerals Forum, discussion and message board

[vic rzonca]

A bezoar is a lump of hardened, undigested material found in the gastrointestinal tract of deer, antelope, goats, oxen and llamas. It forms when layers of calcium and magnesium phosphate build up around a small bit of plant fiber or a pebble. Stomach contractions squeeze and smooth it into a roughly round shape. Bezoars had value because they were believed to have the power of a universal antidote against any poison. Tradition held that a drinking glass which contained a bezoar would neutralize any poison poured into it. Not recommended by nine out of ten physicians, for poisonings.

[Tracy]

humans form bezoars too...but not ones made of apatite. :)

[cascaillou]

we can also (painfully) form whewellite