Gunpowder, also known as black powder, is a mixture of sulfur, charcoal, and potassium nitrate (saltpeter). It was historically used as the earliest known chemical explosive and remains the only explosive whose ingredients are in the solid state. Its scent profile is distinct and recognizable.
The primary aroma of gunpowder is mildly sulfurous, akin to the smell of matches or fireworks, largely due to the sulfur content. When gunpowder burns, it releases a pungent, acrid smell that is sharp and can be somewhat metallic. The smoke produced carries a heavy, tangy odor of burnt wood and earth, primarily contributed by the charcoal. Additionally, there is a faint, bitter note from the potassium nitrate which can resemble the smell of mineral salts.
Unburnt gunpowder has a slightly musty, earthy smell, mingled with the sharpness of sulfur. Overall, its scent can be described as intensely pungent, with smoky and mineral qualities, reminiscent of an ignited firework or a struck match, fading into a more complex, burnt organic aroma.