Inn villages people believe that the aged Nagas will swallow this and vomit it whenever it needs light...
In Tamil, its name is manickam. In silappathigaaram, kannagi proved her husband is innocent by breaking his silambu contains manicka paral, but the pandya's silambu contains muthu (pearl) paral.
Dear friends Ihave heard of this Nagarathinam story . When acobra happens to live its entire life span without exhausting its much of its poison, it converts into a kind of hard solid material whichposessessome radiation emitting properties. The snake becomes very short and fat.
Using this stone on vomitting , snake attracts its preys to fall into its domain of hunt. People used to throw cow dung on it and kill the snake which becomes half blind on close up of this stone.This kind of stone are availe in the countries whichlies exactely on equatorwhere very poisonous snakes are in plenty.