Colors in Fireworks
Pyrotechnics is the art of making fireworks, which produce different colours when lit. The art involves the intimate mixing of a fuel (burnable material) that is in a fine state of subdivision and an oxidising agent using a binder. This burning coincides with the fuel oxidizer interaction. The binder also burns in air and that adds to flame formation. The effects, so produced owe their selective light emission to the presence of the various elements and compounds. These are summarized below:
- Aluminium is used to produce silver and white flames and sparks. It is a common component of sparklers.
- Barium is used to create green colors in fireworks.
- Carbon is one of the main components of black powder, which is used as a propellant in fireworks. Carbon provides the fuel for a firework.
- Calcium is used to deepen firework colors. Calcium salts produce orange fireworks.
- Chlorine is an important component of many oxidizers in fireworks. Several of the metal salts that produce colors contain chlorine.
- Cesium compounds help to oxidize firework mixtures. Cesium compounds produce an indigo color in fireworks.
- Copper produces blue-green colors in fireworks and halides of copper are used to make shades of blue.
- Iron is used to produce sparks. The heat of the metal determines the color of the sparks.
- Potassium nitrate, potassium chlorate, and potassium perchlorate are all important oxidizers. The potassium content can impart a violet-pink color to the sparks.
- Lithium is a metal that is used to impart a red color to fireworks.
- Magnesium burns a very bright white, so it is used to add white sparks or improve the overall brilliance of a firework.
- Phosphorus burns spontaneously in air and is also responsible for some glow in the dark effects.
- Sulfur is a component of black powder, and as such, it is found in a firework’s propellant/fuel.
- Strontium salts impart a red color to fireworks.
- Zinc is a bluish white metal that is used to create smoke effects for fireworks.