Firedust is the processed, finely ground form of phosgolute, a naturally occurring Oceanykan rock bearing an unusual combination of phosphorus, aluminium, and sulphur compounds in a configuration that has no conventional geological explanation. In its raw state, phosgolute is inert and stable. Ground to a fine powder and dried, the resulting firedust is a low explosive with performance characteristics that significantly exceed modern smokeless powder.
The pressures generated by firedust deflagration are higher than those of standard nitrocellulose propellants, but the more operationally significant difference is thermal: combustion temperatures run approximately a thousand degrees Celsius hotter, owing to the aluminium content which undergoes thermite-like oxidation during the burn. This has two practical consequences. First, firedust-propelled projectiles carry substantially more kinetic energy for a given cartridge volume. Second, firedust accelerates barrel wear dramatically; conventional steel barrels used with firedust cartridges typically reach end-of-life in a fraction of their standard service life. This is why firedust sees the widest use in conjunction with Bluemetal mechanical components, which can tolerate the additional thermal stress.
Firedust is also used in Oceanykan industry as a cutting and blasting agent, and in certain artisan and military explosive devices. Its handling requires care: while significantly more stable than black powder, firedust ignites readily and the aluminium content makes the resulting fire difficult to suppress with conventional methods.
Standardised firedust cartridges are manufactured by a small number of licensed Oceanykan firms. The best amongst these are Armour Piercing Hellshot cartridges for small arms and APFSDS Hellshot for cannon. Unlike other algeochemical products, the export of firedust is not regulated by Federal law, owing to its relative accessibility.