What is fulminated mercury?

Fulminated mercury is an explosive compound that is highly sensitive to shock and friction. It is often used to trigger other, less sensitive explosives, such as TNT, dynamite and plastic explosives.

The preparation of mercury fulminate involves dissolving mercury in nitric acid and then adding ethanol to the solution. Although mercury fulminate was once used to initiate the firing of muzzle-loading firearms and later as a primer for rifle and pistol ammunition, it has since been replaced. The chemical substance is non-corrosive, but it weakens over time. Substances like tetrazene and lead azite are less toxic and remain stable over longer periods of time.