Cyanide

Cyanide, which usually refers to the chemical sodium cyanide but includes any chemical with a Carbon-Nitrogen group, is a naturally occuring highly toxic chemical. It is found naturally in small quantities the pits of many stone fruits, such as peaches and wild almonds. However, it can also be produced artificially.
It's primary industrial use is to separate gold from it's ore.
Cyanide at Wikipedia
Category:Toxins