Several soldiers from the Spanish Air Force observe a Eurofighter EF-2000 fighter aircraft of the Spanish Air Force, as it flies during the Ocean Sky 2023 Military Exercise for advanced air-to-air training in the southern airspace of the Canary Islands, Spain on October 25, 2023. (Photo by Borja Suarez/Reuters)

A protester reacts as police use water cannon during a demonstration to demand changes in the Chilean education system in Santiago, Chile June 25, 2015. (Photo by Ueslei Marcelino/Reuters)

Burmese children attend classes at a government run school December 14, 2011 in Waw township, Myanmar. The education system is based on the United Kingdom's system, after nearly a century of British and Christian presences in Burma. (Photo by Paula Bronstein/Getty Images)

An Israeli missile is launched from the Iron Dome missile system in response to a rocket launch from the nearby Palestinian Gaza Strip, on March 12, 2012 near Ashdod, Israel. (Photo by Uriel Sinai/Getty Images)

Penitentiary system guards carry an inmate with symptoms related to the novel coronavirus at the COVID-19 unit of San Juan de Dios hospital in Guatemala City on July 13, 2020. (Photo by Johan Ordonez/AFP Photo)

Children playing on Walled City rooftop in Hong Kong, 1989. The lack of formal governance in the Walled City led to challenges, but it also fostered a unique system of informal social order. (Photo by Greg Girard/The Guardian)

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.

Russian servicemen stand next to a Russian Yars RS-24 intercontinental ballistic missile system before a rehearsal for the Victory Day parade, with the Moscow International Business Center also known as “Moskva-City” seen in the background, at a range in Moscow, Russia, May 5, 2016. (Photo by Maxim Shemetov/Reuters)