A small, granular substance with a dark gray to black color, resembling coarse sand or fine gravel. The particles are irregular in shape, with a slightly reflective surface due to the nitrates and sulfur content. The texture is gritty and loose, easily shifting when handled, with occasional clumps formed by moisture or compression. Stored in a worn, small cloth pouch or a rusted metal tin, showing signs of frequent use and rough handling in a post-apocalyptic setting.