Gunpowder

Gunpowder or blackpowder was a substance that existed across many worlds in the multiverse that was similar to the magic alchemical substance known as smokepowder.

Description
Typically gunpowder would ignite (burn with an open flame) and explode (burn very rapidly), but there were a number of crystal spheres where this was not the case. And in some such worlds, gunpowder brought into them from another would be rendered inert.

Creation
Charcoal, nitre, and sulfur were components of this substance.

Availability

 * Gunpowder could be found on Toril, but due to to powerful magics cast by the deity Gond the substance was inert. On rare occasions, Gond would allow high-ranking priests of his church to divinely enchant gunpowder into a non-inert state, but never enough to threaten the dominance of smokepowder. These priests were willing to sell this gunpowder, but only to those that sought to use it for the greater glory of their deity.
 * In Loudwater, the local apothecary sold gunpowder.

Beyond the Realms

 * Earth, a planet where gunpowder functioned normally.
 * Krynn was known to lack gunpowder.
 * Oerth, where the planet's local magic and physics rendered gunpowder inert.
 * Beyond the Prime Material plane, gunpowder could be found in the Domains of Dread, such as Barovia.

History
Over time Gond witnessed many members of his Church's clergy, as well as devout lay worshipers, die from experimenting with gunpowder whilst creating new mechanisms for his greater glory. Fearing that he might lose worshipers too fast and that other mortals might be frightened, shunning his faith, Gond used powerful magics to render gunpowder inert on Toril.

During the Time of Troubles, Gond in his mortal avatar form washed up on the shores of Lantan. To reward his followers there for sheltering him, he revealed to them the secret of how to make the alchemical substance smokepowder as an alternative to gunpowder, which due to precise proportions of a magical ingredient could circumvent his magics, allowing it to ignite and explode. He also revealed to them how to create firearms utilizing the substance that were safe and reasonably accurate.

Firearms

 * On worlds where it was not inert, gunpowder was primarily used for firearms.
 * Gunpowder wands were one of the few firearms in the Realms that operated on specially enchanted gunpowder.

Other Uses

 * In the Realms some were known to use it as a powder, polishing ferrous metals with it to remove all rust.
 * Some in the Realms would encase metal items in a bucket, dish, or even larger cask of wetted gunpowder to thoroughly remove all corrosion.

Trivia
Wizards could learn how to make gunpowder from the spell Alamir's fundamental breakdown.