An artificially manufactured version of a goa stone found inside the stomachs of an animal (bezoar stones) and its case. Made in India from a paste of clay, crushed shell, amber, musk and resin and used for numerous complaints such as poisons.
Photograph 18th and 19th Century

Credit: Wellcome Library, London

A bezoar (/ˈbiːzɔər/, from Persian bazahr, "antidote") is a mass found trapped in the gastrointestinal system (usually the stomach),[2] though it can occur in other locations.[3][4] A pseudobezoar is an indigestible object introduced intentionally into the digestive system.[5]

There are several varieties of bezoar, some of which have inorganic constituents and others organic.

Read more on the Wiki:

http://en.wikipedia.org/wiki/Bezoar