Enstreng (ENN-strehng)

Enstreng is the in-world version of gunpowder, and was created/discovered via metallurgy experiments by Devatksa Acosaphaura in 951AC following her exploration of past reports of accidental/coincidental reactions between its components. It was her first significant contribution to current civilized culture and led to her acceptance as an apprentice of Yerga'renona Iatix, a previously-fringe member of the Ustrarian Gild of Craftsmen.
The decades prior to the War of the Six experienced a period of rapid related technological growth, including its first recognizable firearms (at which the Acosaphaura especially became adept), but received significant pushback from skeptics and religious bodies concerned over its source materials: 

• agokil (in-world sulfur) in particular was only found at the time in remote, dangerous, and "demon-associated" locations (in actuality, many of these were eisorcei clutches) 
• The relative mystery of the creation of saltpeter was seen as sorcery, even if it was little different from the refinement of charcoal. 
• The fourth ingredient, kelaqgux (or simply 'gux'), was used as a stabilizer for the process and gave the chemical reaction a characteristic fuchsia flame -- it too was considered controversial, since it was made from minerals mined at the Eizunuth Veil of the Creqira.

This coincided with a general cultural renaissance and surge in ideas of "civilized engagement" with the world at large: the Order of the Burning Crown was now the predominant religion in Ustraria, warlocks and other instances of harmful uses of Aré-Ega, and so on. As a result, the ratification of the Quelldraw Act in 964AC was well-received -- it was easy to label use of a firearm as uncivilized and ultimately class it as a warcrime, and outlaw possession of both firearm and enstreng.
There were two additional interruptions: not only the arrival of war, but the increasing scarcity of kelaqgux even were it permissible to mine. This has led to an extreme shortage in enstreng generally that most cultures do not lament.

Utility

Firearms, explosives

Social Impact

Sixty-two people (and, Devatska would note, "one unborn child" -- hers) died in the search for viable enstreng, either through experimentation accidents, attacks by thieves or the competition, or otherwise. Likewise, enstreng was found at the Korzhun Holding following the Massacre of the 215th Holding, which was generated further, more recent scorn.
It is also known colloquially as 'death dust'.

Inventor(s)

Devatska Acosaphaura

Access & Availability

Rare, outlawed

Complexity

Relatively complex in both chemical and technological terms.

Related Materials

• Agokil
• Kelaqgux