People cool off at Crown Fountain in Millennium Park as temperatures reached a record high of 97 degrees Fahrenheit on June 17, 2024 in Chicago, Illinois. Temperatures in the city are expected to reach highs in the 90s for the remainder of the week. (Photo by Scott Olson/Getty Images)

Edgar Sanchez stops on a walk with his dogs who cool off in a pool beside a fire hydrant sprayer, Saturday, June 22, 2024, in the Lower East Side neighborhood of New York. (Photo by John Minchillo/AP Photo)

England fans react as they watch a live broadcast of the Women's Euro final football match between England and Spain, at Boxpark Wembley in London on July 27, 2025. (Photo by Niklas Halle'n/AFP Photo)

A customer grimaces in pain as she gets a tattoo on her arm at the 21st International Tattoo Convention Berlin on December 3, 2011 in Berlin, Germany. The annual tattoo trade fair runs from December 2–4, 2011. (Photo by Adam Berry/Getty Images)

U.S. President elect Barack Obama kisses his wife Michelle as Vice-President elect Joe Biden (right) embraces his wife Jill after Obama gave his victory speech during an election night gathering in Grant Park on November 4, 2008 in Chicago, Illinois. (Photo by Scott Olson/Getty Images)

A Zombie Santa is pictured Death Yard Haunted Attraction in Hendersonville, Tennessee December 10, 2014. The Nashville-area haunted house is getting into the Christmas spirit this weekend, with Zombie Santa, his undead elves and a demonic reindeer going on the attack for fun and charity. (Photo by Harrison McClary/Reuters)

In this photo taken on Saturday, November 16, 2013, Mt. Etna, Europe's most active volcano, spews lava during an eruption as seen from Acireale, near the Sicilian town of Catania, Italy. (Photo by Carmelo Imbesi/AP Photo)

The mineral pyrite, or iron pyrite, also known as fool's gold, is an iron sulfide with the formula FeS2. This mineral's metallic luster and pale brass-yellow hue give it a superficial resemblance to gold, hence the well-known nickname of fool's gold. The color has also led to the nicknames brass, brazzle, and Brazil, primarily used to refer to pyrite found in coal.
In crystallography, the cubic (or isometric) crystal system is a crystal system where the unit cell is in the shape of a cube. This is one of the most common and simplest shapes found in crystals and minerals.