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.

Actor Sophie poses on September 5, 2022 in various locations in character at the Goodwood Race Track ahead of next week Goodwood's Revival meeting (16-18 September). (Photo by Peter Tarry/The Times)

Naked footballers participate in a Germany v Netherlands soccer match in protest against what they say is increasing commercialization of professional football, in Wuppertal, Germany on September 6, 2020. (Photo by Leon Kuegeler/Reuters)

Workers from the South Florida Science Center and Aquarium and Imagine Exhibitions put together an animatronic spinosaurus outside the science center in West Palm Beach, Fla., Tuesday, October 27, 2015. The giant spinosaurus is part of the Dinosaurs Around the World exhibit, set to open on November 1. (Photo by Maria Lorenzino/South Florida Sun-Sentinel via AP Photo)

Frog legs it! Indonesian flying frog tries to hitch a ride on snail's back before realising it would be quicker to hop it alone. A tiny frog struck up an unlikely friendship with a giant African land snail after clambering onto its shell to catch a ride. (Photo by Hendy Mp/SOLENT/Visual Press Agency)

Emma Navarro of the U.S. celebrates with supporters after beating Veronika Kudermetova of Russia in their second round women's singles match at the Wimbledon Tennis Championships in London, Thursday, July 3, 2025. (Photo by Joanna Chan/AP Photo)

A dragonfly rests on a leaf in Hinojedo, Cantabria, northern Spain, 01 June 2023. (Photo by Pedro Puente Hoyos/EPA/EFE/Rex Features/Shutterstock)

These photos and video were taken in the Russian city of Astrakhan on the evening of June 7th, 2012. (Photo by Maxim Korotshenko)