Coloring the Sky, Powering our Lives

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As the brilliant blooms burst above you this Fourth of July, you might wonder how they get those brilliant colors. 

As the brilliant blooms burst above you this Fourth of July, you might wonder how they get those brilliant colors. The answer is from minerals! Each color is the result of specific chemicals that are derived from minerals. Come find out what these minerals are, and get ready to be surprised at the other ways we use these minerals when they’re not competing with the stars to illuminate our night skies.

Green fireworks, courtesy of PublicDomainImages
Green fireworks, courtesy of PublicDomainImages

The Color: Green

The Chemical: Barium Chloride

Mineralogy 101: Barium chloride is what’s known as a metal salt. The barium, though, comes from minerals, mostly commonly from barite.

Its Other Uses:

Most people’s personal experience with barium likely is tied to the doctor’s office. Because barium is not absorbed by the body but is very good at blocking radiation, people suffering from a variety of digestive issues are often given a barium ‘milkshake’ prior to having x-rays or scans of the esophagus, stomach, or small intestine. Once these organs are coated with barium, they stand out more clearly on the scan, allowing easier detection of irregularities. Barium’s ability to absorb radiation is also why barite is commonly used in the concrete of radiation shielding in hospitals, laboratories, and nuclear facilities.

Medical applications, however, represent a very small percentage of barite used in the United States.  Over 95 percent of the barite sold in the United States is used in the oil and gas industry. The name barite is derived from the Greek word for heavy. Because of this property, barite is used as a weighting agent in liquids used for drilling oil and gas wells. The weight of the drilling mud suppresses high pressure from the oil and gas and helps prevent blowouts.

Where Does It Come From/Where Does It Go: In 2014, the United States relied on other countries for 79 percent of its barite supplies, with China having the largest reserves. Most U.S. production comes from four mines in Nevada.

Blue fireworks, courtesy of Standard221, Wikipedia.org.
Blue fireworks, courtesy of Standard221, Wikipedia.org.

The Color: Blue

The Chemical: Copper chloride

Mineralogy 101: Like barium chloride, copper chloride is a metal salt. There are several natural, but relatively rare, mineral forms of it—eriochalcite, nantokite, and tolbachite.

Its Other Uses: Copper was one of the first metals used by humans and has played an important role in the development of civilization. The vast majority of copper today is used for electrical purposes, such as generating power and transmitting it.

Where Does It Come From/Where Does It Go:  The largest reserves of copper in the world are found in Chile, which is also the single largest producer of copper. In the United States, Arizona and Utah accounted for the majority of domestic copper production. In 2014, the United States produced about 70 percent of its copper supplies. China accounted for 40 percent of global copper consumption, and the United States accounted for about 8 percent.

Yellow fireworks, courtesy of Adam Berman, Wikipedia.org.
Yellow fireworks, courtesy of Adam Berman, Wikipedia.org.

The Color: Yellow

The Chemical: Sodium Nitrate

Mineralogy 101: Another salt, sodium nitrate’s mineral form is known as nitratine.

Its Other Uses: Although salts are a general class of chemicals, sodium is probably the most commonly associated metal with salts. Sodium forms many different salts, each of which has various uses.

The most common and abundant sodium salt is sodium chloride. Although well known as table salt, sodium chlorides major uses include highway deicing, chemical feedstock, and food processing.

Sodium nitrate is a type of saltpeter, which is most famously used in the production of gunpowder.

Sodium sulfate is another commonly used sodium salt, which has many uses. Sodium sulfate is used in the glass-making industry to remove air bubbles; in textiles to allow for even absorbtion of dyes; and as filler in detergents and wood pulp paper.

A fairly new use for salts such sodium sulfate and sodium nitrate is as thermal energy storage, since they can absorb quite a bit of heat and then slowly release it.

Where Does It Come From/Where Does It Go: The United States ranked second in global salt production behind China. Global reserves of salt are large. Economic and subeconomic deposits of salt are substantial in principal salt-producing countries. The oceans contain a virtually inexhaustible supply of salt.

Red fireworks, courtesy of Don-vip, Wikipedia.org.
Red fireworks, courtesy of Don-vip, Wikipedia.org.

The Color: Red

The Chemical:  Strontium nitrate

Mineralogy 101Strontium is element number 38 on the periodic table, and commonly occurs in nature, but seldom in quantities sufficient for economical recovery. The strontium nitrate used in fireworks is actually a strontium salt, and the source of the strontium is usually the mineral celestite.

Its Other Uses:  In the U.S. about 30 percent of strontium compounds have been used for pyrotechnics and signals; it is also used in ceramic ferrite magnets (like refrigerator magnets and for small motors), master alloys to make aluminum castable, in the electrolytic production of zinc, and as an additive in glass.   Since 2006 it is thought that virtually all the strontium minerals consumed in the United States were used in drilling fluids for oil and gas wells, not to make other strontium compounds.

Strontium compounds are used as an active ingredient in toothpastes for temperature-sensitive teeth and as a pain reliever for some types of cancer. Although specific information is not available, these uses likely consume very small quantities of strontium compounds, but the compounds must be extremely pure.

Where Does It Come From/Where Does It Go: The world reserves of strontium minerals are estimated to be 6.8 billion tons. They are mined in Spain, China, Mexico, Argentina and Morocco.  Deposits of strontium minerals occur widely in the United States, but none have been mined in the domestically since 1959. The U.S. relies 100 percent on imports for strontium minerals.

Purple fireworks, courtesy of Ethically Yours, Wikipedia.

We leave you with the color purple, which is made up of a combination of strontium and copper, described above. So as you enjoy your Fourth of July, don’t forget that minerals made those fireworks possible, just as they make so many other things we rely on possible every other day of the year.

Want more fun information on minerals? Check these out or follow us on www.twitter.com/usgsminerals.