Fulminic salt

Fulminic salt is an explosive mineral substance, notorious for hazardous to handle and its highly explosive nature. Other names for it include thunderstone, boomstone, Fire-Heart's powder and Gowyr's tears

Properties

Fulminic salt has a characteristic of pale cyan color, and it has a potently acrid smell which is usually the first indicator of the substance's presence.
The salt is notoriously volatile, prone to violent explosion if dropped or otherwise impacted with great force. When processed, salt crystals should be split by carefully bending or using a wedge, rather than smashing it with a hammer or pick. It can also be grated with a special rasp or ground, but the ensuing vast amounts of powder are corrosive to breathe and are known to kill workers within minutes of constant exposure to them.
Though naturally occurring, alchemists have recognized fulminic salt to be imbued with residual magical energy. However, none can say where or when it is loaded with said energy, or what conditions lead to its creation.

Occurrence

Fulminic salt is a rare substance, found primarily near sites of volcanic activity and in noxious fissures within the earth. In such natural deposits, it appears as needle-like crystalline formations, which can climb into impressive heights and form splintered latticeworks of salt.
The substance itself is safe to handle, but the environments where it is harvested are are fraught with hazard. Acidic waters and toxic fumes from within the heart make the surroundings poisonous for most forms of life, and the salt itself is deadly if breathed in its powdered form.
The dwarven town of Kiram is built atop a site particularly rich in the substance, and the town lives and thrives on its harvest. Extesively guarded shipments of fulminic salt flow downstream from the Worldscar Mountains towards Lake Oremar and Lake Achernega, from where the shipments find their way to other parts of Mundus.

Applications

Fulminic salt's explosive properties have been utilized in the mining industry to excavate deposits, or to neutralize caverns which are too winding, vertical or narrow to safely clear of dangerous creatures using conventional methods.
Firearms which utilize the material's properties have been devised through the years, but due to the difficulty of reliably forming explosive charges of the right shape and size, these have been left mostly experimental. Grenades, bombards and other explosive devices are an expensive, but potent weapon fielded throughout the continents.
When it comes to firearms, The ashurtarâg are the notable exception. Their craftsmen have devised some well-guarded and secret method to circumvent this issue, and are known to field various kinds of (relatively) sophisticated firearms. They use these to great effect against the setzá who occasionally try to raid their fortified towns, as well as the undead which are a constant threat from the Alhara Desert to the east.