Explosive powder used in ammuntion [sic]
Gunpowder is the earliest known chemical explosive, accidentally invented in China. It is simply a mixture of charcoal, sulfur, and saltpeter, and is widely used as a propellant due to its slow-burning properties. The use of gunpowder began to decline in the 19th century, though some munitions still use gunpowder today.
Difficult to obtain, but can usually be found in some munitions.