The chrysanthemum firework effect is a classic aerial display, defined by a perfectly symmetrical, spherical burst where each light source leaves a visible tail of sparks as it flies outward. The pyrotechnic shell launches skyward, and at its peak altitude, a timed internal charge disperses numerous burning pellets, known as stars. These stars burn long enough to visibly streak across the sky, creating a dense, blooming sphere of radiating lines of light.
Appearance and Unique Characteristics
The visual experience of a chrysanthemum shell begins with a near-perfect sphere of light that expands rapidly across the night sky. Unlike other spherical bursts, the chrysanthemum’s stars leave a trailing effect, often described as a stream or a tail, which gives the pattern a full, brush-stroke appearance. This visual is sometimes referred to as “fire dust” or a “sparkle trail,” where the embers follow the star’s trajectory before fading.
The symmetry of the burst is a deliberate outcome of the shell’s construction, resulting in a uniform pattern of streaks that radiate evenly from a central point. The colors of the display are determined by the metallic salts incorporated into the star composition, allowing for a wide palette of effects. Vivid blues are achieved using copper compounds, while reds come from strontium salts, and gold or silver effects are often created with various metal powders. The burst’s size is impacted by the strength of the central charge and the composition of the stars, which must be calibrated to burn for a sustained time.
Internal Mechanics of the Burst
The trailing tail of a chrysanthemum firework is achieved through a star composition designed for a prolonged burn. Each star is a small, pressed pellet containing a fuel, an oxidizer, and a colorant, often coated with a specialized pyrotechnic mixture. This outer coating is typically rich in charcoal, which is the component responsible for the visible tail of light.
The charcoal is mixed with an oxidizer like potassium nitrate, which ensures the material continues to burn as it is propelled through the air. The resulting glowing charcoal sparks are what spectators see as the trail, a phenomenon sometimes called a streamer arm or tendril. Pyrotechnicians use high-charcoal formulas, such as those known as Chrysanthemum 6 or 8, which are slow-burning black powder variations with a high ratio of charcoal to oxidizer. The sustained ignition is initially maintained by the oxidizer within the star, and the surrounding air helps to keep the ember-like sparks alive, creating the signature long, visible streak.
Comparing Chrysanthemum to Other Shell Types
The chrysanthemum firework is most frequently compared to the peony shell, but the distinction lies in the star’s behavior. A peony shell creates a spherical burst of colored stars that do not leave a trail, resulting in a cleaner, more rounded globe of light. In contrast, the stars of a chrysanthemum are formulated to burn longer and visibly streak outward, making the overall effect appear fuller and more dynamic.
Another related effect is the willow shell, which also features a trailing effect. Willow stars are engineered to produce long, drooping, cascade-like trails of silver or gold that fall toward the ground, resembling the branches of a willow tree. The chrysanthemum’s trails are shorter and radiate stiffly outward in a spherical pattern, rather than producing the long, arcing descent seen in the willow effect.