Gold granules are displayed at the Prioksky Non-Ferrous Metals Plant in Kasimov, Russia February 14, 2017. (Photo by Sergei Karpukhin/Reuters)

“A Double Eagle is a gold coin of the United States with a denomination of $20. (Its gold content of 0.9675 troy oz was worth $20 at the then official price of $20.67/oz). The coins are made from a 90% gold (0.900 fine = 21.6 kt) and 10% copper alloy”. – Wikipedia

Photo: A “Double Eagle” gold twenty dollar coin is displayed above a catalogue picture showing the reverse side of the coin at Goldsmith's Hall on March 2, 2012 in London, England. Nearly half a million of these coins were originally minted in the midst of the Great Depression in the US. Only 13 are known today after the rest were melted down before they ever left the US Mint, sacrificed as part of a strategy to stabalise the American economy. In 2002 a Double Eagle sold at auction for $7.6 million. (Photo by Peter Macdiarmid/Getty Images)

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.

A member of staff at Morton & Eden holds an extremely rare early Islamic gold coin on Thursday September 12, 2019, which is expected to fetch £1.4m at auction in London. Measuring a 20mm across, about the size of a modern £1 piece, it is one of the world's rarest and most treasured Islamic gold coins from the first dynasty of Islam, the Umayyad gold dinar dated 105h (723AD). (Photo by Victoria Jones/PA Images via Getty Images)

Creative imagery, gold winner: Sprats and Bread, Ruediger Schulz, Germany. (Photo by Ruediger Schulz/2021 Bird Photographer of the Year)

Two helicopters are seen following a collision near Seaworld, on the Gold Coast, Australia, 02 January 2023. Four people are dead and another 13 injured after two helicopters collided before one crashed into the Broadwater on the Gold Coast. (Photo by Dave Hunt/EPA/EFE/Rex Features/Shutterstock)

Guns decorated with gold and jewellery are displayed in the Drugs Museum, used by the military to showcase to soldiers the lifestyles of Mexican drug lords, at the headquarters of the Ministry of Defense in Mexico City, October 14, 2016. (Photo by Henry Romero/Reuters)

Thailand's badminton player Ratchanok Intanon, who hopes to win gold at the Rio Olympics, receives a massage during a morning training session at a gym in Bangkok, Thailand, June 22, 2016. As the humble daughter of factory workers at a Bangkok sweet-maker, badminton was a ticket out of poverty for Ratchanok Intanon, who hopes winning gold at the Rio Olympics might inspire more Thai girls to chase their dreams. (Photo by Athit Perawongmetha/Reuters)