Gold is a precious metal that has been valued throughout human history for its beauty, malleability, and rarity. It has long been used as both money and a store of value. Many things are related to gold in different ways, from its physical properties and uses, to its role in history, economics, and culture. This article will explore the many connections and relationships gold has in science, industry, finance, and beyond.
Physical Properties
Gold is a dense, shiny yellow metal that is soft, malleable, and ductile. It has a melting point of 1,064°C and is very resistant to corrosion and most chemicals. Some key physical properties related to gold include:
Atomic Structure
– Symbol: Au
– Atomic number: 79
– Atomic weight: 196.967
Gold has 79 protons and electrons, with 118 neutrons in its most abundant isotope. It is a transition metal belonging to group 11 on the periodic table.
Color
– Gold’s distinctive yellow color is due to the strong absorption of blue light.
This is caused by relativistic effects affecting the outer electrons as gold has a high atomic number. The absorbed light excites electrons which then emit photons in the yellow part of the spectrum.
Density
– Density: 19.3 g/cm3
Gold has a very high density, almost twice that of lead. This arises from its tightly packed crystalline structure and high atomic weight.
Malleability
– Gold is the most malleable metal.
A single gram of gold can be beaten into a sheet of 1 square meter. Gold foil can be made thin enough to appear transparent. This allows gold to be easily shaped, stamped, and embossed for jewelry, coins, electronics, and more.
Ductility
– Gold is also very ductile.
It can be drawn into a fine wire or thread. Just one ounce of gold can be worked into a wire 50 miles long. This makes gold ideal for wiring and plating.
Chemical Properties
Some key chemical attributes of gold include:
– Relatively inert – does not tarnish or corrode easily
– Does not react with oxygen or water
– Resistant to most acids, but dissolves in aqua regia (mix of nitric and hydrochloric acids)
– Does not react readily with halogens like chlorine or fluorine
– Can form complexes with cyanide ion
– Readily alloys with many other metals like silver, copper and zinc
These properties arise from gold’s electron configuration and make it ideal for coins, jewelry and electrical contacts. Gold resists oxidation and corrosion even at high temperatures. While not the most reactive, gold can dissolve in certain solutions like mercury or alkaline thiourea.
Geology and Mining
Several geological factors relate to the occurrence and mining of gold:
Natural Abundance
– Gold makes up around 0.003 parts per million of the earth’s crust.
This makes it a relatively rare metal. Gold often occurs as a free element but can also be in minerals like calaverite, sylvanite, nagyagite and petzite.
Ore Deposits
– Gold most often occurs in quartz veins and alluvial deposits.
Gold-bearing quartz veins are formed when hydrothermal fluids deposit gold within fractures in rock, often with pyrite and other sulfide minerals. Alluvial gold eroded from rocks can collect in stream beds as placer deposits.
Mining Techniques
– Methods for mining gold include placer mining, panning, sluicing, dredging, hard rock mining and by-product mining.
Cyanide leaching is used to extract gold from low grade ores. Some miners also use mercury, although this practice is being phased out due to health risks.
Major Producers
| Country | 2020 Production (tonnes) |
|---|---|
| China | 368 |
| Russia | 330 |
| Australia | 325 |
| United States | 190 |
China, Russia and Australia are the world’s largest gold producing countries, accounting for over 50% of total annual production. South Africa, Canada and Peru are other major producers.
Uses
Some of the main uses of gold that relate to its properties include:
Jewelry
– Gold is prized for jewelry and decoration due to its luster, workability, and resistance to tarnish.
Gold jewelry represented over 50% of global gold demand in 2020. Gold is alloyed with other metals like silver, copper and zinc to increase hardness and vary color. Popular gold alloys include 18k yellow gold (75% Au, 15% Ag, 10% Cu).
Investment
– Gold coins, bars and exchange-traded funds provide a way to invest in gold.
Central banks and investors hold gold as a store of value and hedge against inflation or economic crisis. Around 20% of gold demand comes from investment.
Electronics
– Gold is used in electronics due to its conductivity, resistivity to corrosion and ability to be drawn into fine wires.
Gold bonding wire and plating improve conductivity and reliability in circuits, connectors and switches. About 8% of gold is used in electronics.
Dentistry
– Gold alloys are used for fillings, crowns, bridges and orthodontic appliances due to gold’s biocompatibility and resistance to wear.
Other uses of gold include glassmaking, radiation shielding, antibacterial coatings, pharmaceuticals and aerospace applications.
History and Culture
Gold has played an important role in human history, culture and the arts:
Early History
– Gold artifacts dating back over 6,000 years have been found, showing its early value.
Ancient civilizations like the Egyptians prized gold for jewelry, decoration and rituals. Gold was made into crowns, masks, statues and woven into fabrics.
Economics
– Gold was one of the first metals used as money around 700 B.C.
Coins like the gold stater and gold dinar allowed more complex trade and taxation. Countries tied paper money to the gold standard to stabilize values.
Arts
– Gold appears prominently in art forms like sculpture, paintings, architecture, crafts and mosaics.
Gold leaf adorns religious icons, buildings and book covers. The malleability of gold facilitates beating, gilding and foil making.
Symbolism
– Gold is associated with wealth, power, divinity, wisdom, and immortality across cultures and history.
It represents sun and fire in mythology. Buried gold treasures feature in legends. Royalty and winners are crowned with gold.
Economics and Finance
Key aspects of gold’s role in economics and finance include:
Investment Asset
– Gold is seen as a store of value and safe haven investment in times of crisis. Its price often rises when confidence in paper currencies falls.
Many investors have a small portion of gold in their portfolios. Gold Exchange Traded Funds (ETFs) are popular ways to invest without holding physical gold.
Reserve Asset
– Central banks and the International Monetary Fund hold gold reserves to support financial stability and manage currency risks.
The U.S. has the most official gold reserves at over 8,000 tonnes, followed by Germany, Italy and France.
Commodity Trading
– Gold is actively traded on commodity exchanges and in over-the-counter markets. Spot gold and gold futures are used for speculation and hedging.
Gold trading averages over $250 billion daily. Key gold trading hubs are London, New York, Zurich and Shanghai.
Jewelry Retail
– Jewelry accounts for over 50% of gold fabrication demand. India, China and the United States are the largest gold jewelry markets.
Factors like disposable income, culture, festivals and weddings drive jewelry demand, especially in emerging markets.
Conclusion
Gold has a rich history and wide-ranging applications. Its unique properties make it valuable in jewelry, electronics, dentistry, and numerous other fields. Gold will likely continue playing a key role as money, a commodity, and an investment asset given its cultural significance, existing supply dynamics, and perception as a safe haven. While its nominal price fluctuates, gold retains intrinsic value due to its relative rarity, distinct density and chemical properties. The broad reach of gold into industry, finance and the arts reflects its enduring importance to humankind.
