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), even explode (burn very rapidly) under the right conditions, but there were a number of crystal spheres where this was not the case. And in some such worlds, gunpowder brought in them from another would be rendered inert. These differences in functionality across the Known Spheres was often written off as the whims of deities, done to keep mortals in their place.

Gunpowder was typically sold within either small wooden powderkegs or in powder horns. The latter were typically water-proof, as gunpowder was rendered unusable when exposed to water.

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 was a planet that had gunpowder, but its local magic and physics rendered the substance inert.
 * Beyond the Prime Material plane, gunpowder could be found in the Domains of Dread, such as Barovia.

History
Over time Gond witnessed many mortals dying in explosions from experimenting with gunpowder. This included members of his Church's clergy and devout lay worshipers, who died while experimenting with the substance to create 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 decided to take drastic measures. With the agreement of the goddess of magic Mystra, Gond used powerful magics to render gunpowder inert on Toril, which she then subsumed into the Weave so that the effects permeated all of Toril. This occurred somewhere between 1246 DR and 1356 DR.

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.

Following the Spellplague, while Gond was in a weakened state and the nation of Lantan was in another world, the clergy of Kossuth tried to spread a claim that gunpowder's inert state on Toril was the doing of their god.

Weapons

 * On worlds where it was not inert, one of the primary uses for gunpowder was forming bombs.
 * On worlds where it was not inert, gunpowder was used in bombards to propel heavy balls of cast iron.
 * On worlds where it was not inert, gunpowder was primarily used for firearms,    propelling bullets out from their barrels.
 * 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.