Gold
Gold is a precious metal that has been used for coinage, jewelry, and other arts throughout recorded history. It is the earliest recorded metal employed by humans, with artifacts dating back to the 5th millennium BC.
Pictured funerary gold sandals from Egypts New Kingdom.
Gold is the most malleable of all metals. It can be drawn into a wire of single-atom width, and then stretched considerably before it breaks. A gold nugget of 5 mm (0.20 in) in size can be hammered into a gold foil of about 0.5 m2 (5.4 sq ft) in area.
A total of around 201,296 tonnes of gold exists above ground, as of 2020.This is equal to a cube with each side measuring roughly 21.7 meters (71 ft).
Gold is thought to have been produced in supernova nucleosynthesis, and from the collision of neutron stars, and to have been present in the dust from which the Solar System formed.
On Earth, It most often occurs as a native metal, rarely in pure form but rather as microscopic particles embedded in rocks, as nuggets or in alluvial deposits.
Pictured is an extremely rare gold crystal weighing 1/2lb and valued in $1.5 million.
The world's oceans also contain gold, which if added together would amount to 15,000 tonnes.
The metal has been highly priced by humans all across the world and played an important role in the history of a number of civilizations.
The Aztecs regarded gold as the product of the gods, calling it literally "god excrement" (teocuitlatl in Nahuatl).
In Roman metallurgy, new methods for extracting gold on a large scale were developed by introducing hydraulic mining methods. One of their largest mines was at Las Medulas in Spain, where seven long aqueducts enabled them to sluice most of a large alluvial deposit.
Gold was one of the main objects of desire and corruption that fueled the European exploration and colonization of Mesoamerican and West Africa.
One main goal of the European alchemists was to produce gold from other substances, such as lead — presumably by the interaction with a mythical substance called the philosopher's stone.
Trying to produce gold led the alchemists to systematically find out what can be done with substances, and this laid the foundation for today's chemistry.
75% of the presently accounted for gold has been extracted since 1910, and two-thirds since 1950.
Nowadays, the world consumption of new gold produced is about 50% in jewelry, 40% in investments and 10% in industry.
Because of the softness of pure (24k) gold, it is usually alloyed with base metals for use in jewelry, altering its hardness and ductility, melting point, color and other properties.
Pictured are examples of the first minted coins, made of Electrum, an alloy of Gold and Silver.