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.

Members of the Radio City Rockettes rehearse for the “2022 Christmas Spectacular Starring the Radio City Rockettes” in Manhattan, New York City, U.S., October 19, 2022. (Photo by Eduardo Munoz/Reuters)

In this January 23, 2021, file photo, a police officer detains a young woman during a protest against the jailing of opposition leader Alexei Navalny in Pushkin square in Moscow, Russia. Allies of Navalny are calling for new protests next weekend to demand his release, following a wave of demonstrations across the country that brought out tens of thousands in a defiant challenge to President Vladimir Putin. (Photo by Alexander Zemlianichenko/AP Photo/File)

Dave Woods, 47, waits on an overpass in support for trucks driving in a convoy bound for the nation's capital to protest against coronavirus disease (COVID-19) vaccine mandates, in Wabash Township, Illinois, U.S. March 1, 2022. (Photo by Cheney Orr/Reuters)

A woman reacts after she mades a wreath of flowers during the celebrations of the Kupala night in Pyrohiv, near Kiev, on July 6, 2021. During the celebration, an ancient slavic ritual related to the summer solstice, people wear wreaths, jump over fires and bathe naked in rivers and lakes. (Photo by Sergei Supinsky/AFP Photo)

A child in a Supergirl costume pays respects as Justice Ruth Bader Ginsburg lies in repose under the Portico at the top of the front steps of the U.S. Supreme Court building, in Washington, U.S. September 23, 2020. (Photo by Alex Brandon/Pool via Reuters)

Jasmine Paolini hits a forehand during her first-round US Open match on Sunday, August 24, 2025 at USTA Billie Jean King National Tennis Center in the Flushing neighborhood of the Queens borough of New York City. (Photo by Ray Giubilo)

Models take part in the promotion of the Miss Bumbum (buttocks) beauty pageant, along Paulista Avenue in Sao Paulo, Brazil, on August 7, 2017. The annual Bumbum pageant to select the nation' s sexiest female buttocks will be held on November, 6 in Sao Paulo. (Photo by Nelson Almeida/AFP Photo)