What is "tannerite"

Tannerite is the brand name of a binary explosive marketed primarily for making exploding targets for firearms practice. It is a patented combination of ammonium nitrate (an oxidizer) and aluminum powder (a fuel) that is supplied as two separate powders that are mixed and shaken to produce an explosive. The combination is relatively stable when subjected to forces less severe than a high-velocity bullet impact, such as a hammer blow, being dropped, or impact from a low-velocity bullet or shotgun blast. It is also not flammable – an explosion cannot be created by a burning fuse or electricity. Because it is sold as two separate powders, it can be transported and sold in many places without the legal restrictions that would otherwise apply to explosives. Other combination explosives are generically referred to as Tannerite.