Gold has been a valuable and highly sought-after precious metal for coinage, jewelry, and other arts since long before the beginning of recorded history. In fact, gold standards have been the most common basis for monetary policies throughout human history, and it was not until the late twentieth century that it was replaced with fiat money; money that has a value only because of government regulation or law. When paper money was first introduced, it was typically a receipt redeemable for gold coin or bullion.
Valued in many societies throughout the ages, how we perceive gold has not changed much over the years. Think of how great achievements are often rewarded with gold in the form of medals or trophies; even the Nobel Peace Prize is made of gold. Aristotle in his ethics used gold symbolism when referring to what is now commonly known as the “golden mean”. Similarly, gold is associated with perfect or divine principles, such as in the case of the “golden ratio”. Gold is also associated with the wisdom of aging and fruition: our latter years are considered the “golden years”, and the height of a civilization is referred to as a “golden age”. Even in popular culture gold holds many connotations but is most generally connected to terms which mean good or great, as in the phrases: “has a heart of gold”, “that’s golden!”, “then you’re golden!” and “golden boy”. It also still holds its place as a symbol of wealth and through that, in many societies, success.

Besides its widespread monetary and symbolic functions, gold has many practical uses in fields such as dentistry and electronics. Its high malleability, ductility, resistance to corrosion and conductivity of electricity have led to many uses of gold: electric wiring, colored-glass production and even gold leaf eating to name a few. Au on the periodic table, gold is a chemical element with an atomic number of seventy-nine. Gold is the most malleable of all metals; a single gram can be beaten into a sheet of 1 square meter! Chemically, it is unaffected by air, moisture and most other corrosive reagents, which makes it well suited for use in coins, jewelry and as a protective coating on other, more reactive, metals. However, it is not chemically inert.
Whereas most other pure metals are gray or silvery white, gold is yellow. This color is determined by the density of loosely bound electrons. Common colored gold alloys; a mixture or metallic solid solution composed of two or more elements, such as rose gold can be created by the addition of various amounts of copper and silver. Alloys containing palladium or nickel are also important in commercial jewelry as these produce white gold alloys. Less commonly, the addition of manganese, aluminium, iron, indium and other elements can produce more unusual colors of gold for various applications.
Because of the softness of pure gold, it is usually alloyed with base metals for use in jewelry, altering its hardness, melting point, color and other properties. Alloys with lower karatage, typically 22k, 18k, 14k or 10k, contain higher percentages of copper or other base metals in the alloy. Karat is the unit of purity for gold alloys which is measured as twenty-four times the purity by mass. Therefore, 24-Karat gold is pure, 18-Karat gold is eighteen parts gold six parts other metal, 12-Karat gold is twelve parts gold twelve parts other metal, etc.
Like other precious metals, gold is measured by troy weight and by grams. The price of gold is determined through trading in gold and derivatives markets, but a procedure known as the Gold Fixing in London, which originated in 1919, provides a daily benchmark price to the industry. The afternoon fixing was introduced in 1968 to provide a price when US markets are open. Since April 2001 the gold price has more than quintupled in value against the US dollar, hitting a new all-time high of $1,913.50 on August 23, 2011.
Because gold is mined, there is a limited amount to ever be found. However, most of the gold used in manufactured goods, jewelry, and works of art is eventually recovered and recycled. Thus there is little true consumption of new gold in the economic sense; the stock of gold remains essentially constant (at least in the modern world) while ownership shifts from one party to another. One estimate is that 85% of all the gold ever mined is still available in the world’s easily recoverable stocks, with 15% having been lost, or used in non-recyclable industrial uses.