Noun
A calculous concretion found in the intestines of certain ruminant animals (as the wild goat, the gazelle, and the Peruvian llama) formerly regarded as an unfailing antidote for poison, and a certain remedy for eruptive, pestilential, or putrid diseases. Hence: Any antidote or panacea.
Source: Webster's dictionaryIt was meant as a gift, and, despite its rarity, was considered of equal value to a white deer and a bezoar stone. Source: Internet
Prior to this they were known as "fossil fir cones " and " bezoar stones." Source: Internet