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.

Swimmers known as the Lido Ladies pose by the pool during sunrise at Charlton Lido in Hornfair Park, London on December 2, 2020, on its first day of reopening after the second national lockdown ended and England enters a strengthened tiered system of regional coronavirus restrictions. (Photo by Victoria Jones/PA Images via Getty Images)

Group leader Jane Waithageni Kimaru, 60 years old, shows women how to fight off a potential rapist and escape, during a Taekwondo self-defense class for women in the Korogocho slum of Nairobi, Kenya, Thursday, September 16, 2021. (Photo by Brian Inganga/AP Photo)

Recruits carry ammunition during a military training at a firing range in the Rostov-on-Don region in southern Russia, on October 4, 2022. Russian Defense Minister Sergei Shoigu said that the military has recruited over 200,000 reservists as part of a partial mobilization launched two weeks ago. (Photo by AP Photo/Stringer)

A resident walks on a makeshift walkway above a flooded street from the rising Rio Solimoes, one of the two main branches of the Amazon River, in Careiro da Varzea of Amazonas State, Brazil, June 30, 2015. According to the state Civil Defense, more than 460,000 people were affected by strong rains in the state. (Photo by Bruno Kelly/Reuters)

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)

The Jet Propulsion Lab team's RoboSimian robot turns on a valve at a simulated disaster-response course during day one of the Defense Advanced Research Projects Agency (DARPA) Robotics Challenge finals in Pomona, California, June 5, 2015. (Photo by David McNew/Reuters)

A man carrying buckets walks along a beach littered with piles of debris and plastic waste at the Kedonganan beach in Bali, Indonesia, 19 March 2024. Most of the trash ends up in the sea every rainy season due to the island's lack of a centralized waste management system. (Photo by Made Nagi/EPA/EFE)