mercury fulminate

GNU Webster's 1913

1. n. (Chem.) The mercury salt of fulminic acid (Hg(CNO)2), called also fulminate of mercury. It is an explosive compound prepared as gray crystals, and is used primarily in detonators for detonating high explosives, such as dynamite or TNT. It is sensitive to shock and may be detonated by a blow.

WordNet 3.0

1. n. a fulminate that when dry explodes violently if struck or heated; used in detonators and blasting caps and percussion caps