Dragon's egg
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This article includes a list of references, related reading, or external links, but its sources remain unclear because it lacks inline citations. (February 2014) |
A dragon's egg is a fireworks pyrotechnic star which first burns for a period for a visual effect then explodes with a loud report.
Manufacture of this effect became controversial because of the heavy metals once used, particularly lead tetroxide (Pb3O4). Nowadays, however, bismuth trioxide or bismuth subcarbonate are commonly used as more environmentally friendly substitutes for lead compounds to achieve the effect, and its occurrence in fireworks displays has since become much more common.
Because of its chemical makeup, a shell or cake containing mainly dragon's eggs is often noticeably heavier than a similar device containing other effects.
References
- Croteau, Gerry; Dills, Russell; Beaudreau, Marc; Davis, Mac (2010). "Emission factors and exposures from ground-level pyrotechnics". Atmospheric Environment. 44 (27): 3295. Bibcode:2010AtmEn..44.3295C. doi:10.1016/j.atmosenv.2010.05.048.
- Ledgard, Jared (2006-02-22). The Preparatory Manual of Black Powder and Pyrotechnics. ISBN 9781411685741.