Why Do Fireworks Have Different Colours?

Fireworks give off different colours because of the different minerals that are used to make them. Bright green comes from fireworks made with barium compounds, deep red from strontium compounds, blues from copper compounds and yellows from sodium compounds. In addition, a mixture a strontium and sodium compounds will produce orange light flashes, a mixture of titanium, zirconium and magnesium will produce silver and a mixture of copper and strontium compounds will produce a rich lavender colour. Bright flashes are made using fine ground aluminium powder and larger flakes give the effect of snow.

Fireworks were first used in ancient China, when gunpowder was first discovered. In the USA, people use about 30 000 tons of gunpowder per year to make fireworks for the 4th of July celebrations. About one third of that is used in public fireworks displays, the rest is bought as fireworks to set off at home at parties.