Snake-stone
A snake-stone, also known as a viper's stone, snake's pearl, black stone, serpent-stone, or nagamani is an animal bone or stone used as folk medicine for snake bite in Africa, South America, India and Asia.
The World Health Organization states that it has no effect on snake-bites, bearing in mind that most snake-bites are from non-venomous snakes. They state that traditional medicines and other treatments such as wound incision or excision, suction, or application of "black stones" should be avoided.