Largest commercially available firework

The largest commercially available firework is the Super Crown which is 0.6 m (2 ft) tall, has a 41 cm (16 in) shell and is packed with 34 kg (75 lb) of gunpowder and explosives. These take about eight seconds to reach 488 m (1,600 ft) at which point a second charge at the shell's core scatters golden stars across approximately 0.5 km (0.25 mile), each one burning for a further nine seconds.  To import the Super Crown from China costs £200 plus a further £200 for the mortar (which has a case 5 cm (2 in) thick) to launch the firework. Apart from this, a hole 2 m (6 ft) deep must be dug to house the mortar. The firework uses a range of chemicals to achieve its effects. Iron and the metallic element antimony produce sparks and glitter, red flames are produced from compounds of lithium and strontium, yellowy gold from sodium, blue from copper and green from barium.