About the blog: What Things Are Made Of

AMERICA'S GLOBAL DEPENDENCY FOR NEARLY EVERYTHING


The United States relies on imports for dozens of commodities in everyday use. Often enough, that reliance is 100%. In this book I aim to provide awareness of the hidden geology and mineralogy behind common things, and to develop an appreciation for the global resource distribution that underpins our society. While concerns about oil import reliance are in the news every day, our needs for other minerals are comparable and are typically unknown even to technologically aware Americans.





Sunday, July 4, 2010

A brief introduction to fireworks

Like gunpowder, fireworks are mostly sulfur, saltpeter and carbon but with diverse agents added for color. They originated in China about 1000 years ago as a variation on black powder. April 18 commemorates the invention of firecrackers by Li Tian, a Chinese monk who lived near Liu Yang in Hunan Province, the region that supplies most of the world’s fireworks to this day.

Strontium carbonate (red) and barium chloride (green) tint modern skyrockets and other fireworks. Lighter red may come from lithium carbonate with orange provided by calcium chloride. Blues usually indicate the presence of copper compounds, which also produce purple when mixed with strontium. Rarely, rubidium generates purple. Sodium makes yellow, iron makes gold. Burning titanium, aluminum, or magnesium metal powder is the basis for intense white or silver stars. Strontium also makes red color in highway flares.

More information here.

Photo in public domain, via Wikipedia