earth-wealth.blogspot.com
Gold
History Of Gold As a Metal
4000 BC Gold is first known to be used in parts of Central and Eastern Europe.
3000 The Egyptians master the arts of beating gold into leaf and alloying gold with other metals to achieve variations in hardness and color. They also develop the ability to cast gold, using the lost-wax technique still used in today's jewelry industry.
The Sumer civilization of southern Iraq uses gold to creat a wide range of jewelry, often using sophisticated and varied styles still worn today.
2500 Gold jewelry is buried in the Tomb of Djer, the king of the First Egyptian Dyanisty, at Abydos, Egypt.
1500 The immense, gold-bearing regions of Nubia make Egypt a wealthy nation, as gold becomes the recognized standard medium of exchange for international trade.
The Shekel, a coin originally weighing 11.3 grams of gold, is used as a standard unit of measure throughout the Middle East. The coin contained a naturally occurring alloy called electrum, which was approximately two-thirds gold and one-third silver.
1352 The young Egyptian King Tutankhamun is interred in a pyramid tomb laden with gold, his remains laid in an extravagant gold anthropoid sarcophagus.
1350 The Babylonians begin to use fire assay to test the purity of gold.
1091 Squares of gold are legalized in China as a form of money.
560 The first coins made purely from gold are minted in Lydia, a kingdom of Asia Minor.
58 Julius Caesar seizes enough gold in Gaul (France) to repay Rome's debts.
50 The Romans issue a gold coin called the Aureus.
600-699 AD The Byzantine Empire resumes gold mining in central Europe and France, an area undeveloped since the fall of the Roman Empire. Artisans of the period produce intricate gold artifacts and icons.
1100 Venice secures its position as the world's leading gold bullion market due to its location astride the trade routes to the east.
1284 Venice introduces the gold Ducat, which soon becomes the most popular coin in the world, and remains so for more than five centuries.
Great Britain issues its first major gold coin, the Florin, which is followed by the Noble, the Angel, the Crown, and the Guinea.
1511 King Ferdinand of Spain sends explorers to the Western Hemisphere with the command to "get gold."
1717 Isaac Newton, Master of the London Mint, sets price of gold that lasts for 200 years.
1787 First US gold coin is struck by Ephraim Brasher, a goldsmith.
1792 The Coinage Act places the young United Sates on a bimetallic silver/gold standard, defining the U.S. Dollar as equivalent to 24.75 grains of fine gold, and 371.25 grains of fine silver.
1803 North Carolina site of first US gold rush. The state supplies all the domestic gold coined for currency by the US Mint in Philadelphia until 1828.
1848 The California gold rush begins when James Marshall finds specks of gold in the water at John Sutter's sawmill near the junction of the American and Sacramento Rivers.
1850 Edward Hammong Hargraves, returning from California, predicts he will find gold in Australia within one week. He discovers gold in New South Wales within one week of landing.
1859 The Comstock Lode of gold and silver is discovered in Nevada. As a result, Nevada is made a state five years later.
1886 George Harrison, while digging stones to build a house, discovers gold in South Africa.
1887 Glasgow doctors, Robert and William Forrest, and chemist John S. MacArthur patent the process for extracting gold from ore using cyanide.
1896 Two prospectors discover gold while fishing in the Klondike River in northern Canada, richer finds were rumored farther south in Alaska's Yukon, spawning the Alaska Gold Rush in 1898 -- the last gold rush of the century.
1900 US adopts the gold standard for its currency.
1903 The Engelhard Corporation introduces an organic medium to print gold on surfaces. First used for decoration, the medium becomes the foundation for microcircuit printing technology.
1922 King Tutankhamun's tomb (1352 BC) opened to reveal a 2,448 lb. gold coffin and hundreds of gold and gold-leafed objects (including the mask pictured at the beginning of this section).
1927 A Medical study in France proves gold to be valuable in treatment of Rheumatoid arthritis.
1933 President Franklin D. Roosevelt bans the export of gold, halts the convertibility of dollar bills into gold, orders US citizens to hand in all the gold they possess and establishes a daily price for gold.
1934 Roosevelt fixes price of gold at $35 per ounce.
1935 Western Electric Alloy #1 (69% gold, 25% silver and 6% platinum) finds universal use in all switching contacts for AT&T telecommunications equipment.
1944 The Bretton Woods agreement sets an international gold exchange standard and creates two new international organizations, the International Monetary Fund (IMF) and the World Band. The new standard sets par values for currencies in terms of gold and obligates member countries to convert foreign offical holdings of their currencies into gold at these par values.
1947 The first transistor, the building block for electronics, is assembled at AT&T Bell Laboratories. The device uses gold contacts pressed into a germanium surface.
1960 The laser is invented using gold-coated mirrors to maximize infrared reflection.
1961 Modern-day mining begins in Nevada's Carlin Trend, ultimately making Nevada the nation's largest gold-mining state.
1968 Intel introduces a microchip with 1,024 transistors connected by gold circuits.
On March 15, central banks give up fixed price of gold at $35 per troy ounce and let it free float.
1969 Gold coated visors protect the astronauts' eyes from searing sunlight on the moon (Apollo 11 moon landing).
1970 The charged coupled device is invented, using gold to collect electrons generated by light, eventually used in hundreds of military and civilian devices, including video cameras.
1971 The colloidal gold marker system is introduced by Amersham Corporation of Illinois. Tiny spheres of gold are used in health research laboratories worldwide to mark or tag specific proteins to reveal their function in the human body for the treatment of disease.
1973 The U.S. Dollar is removed from gold standard, and gold prices are allowed to float free. By June, the market for gold in London reaches more than $120 per ounce.
1974 On December 31, US government ends its ban on individual ownership of gold.
1976 The Gold Institute is established in Washington, D.C., to promote the common interests of the gold industry by providing statistical data and other relevant information to its members, the media, government, and the public.
1980 Gold reaches intra-day historic high price of $870 on January 21 in New York.
1986 Gold-coated compact discs are introduced.
1987 Airbags are introduced for cars, using gold contacts for reliability.
1996 The Mars Global Surveyor is launched with an on-board gold-coated parabolic telescope-mirror that will generate a detailed map of the entire Martian surface over a two-year period.
1997 Congress passes Taxpayers Relief Act, allowing US Individual Retirement Account holders to buy gold bullion coins and bars for their accounts as long as they are of a fineness equal to, or exceeding, 99.5 percent gold.
1999 The Euro, a pan-European currency, is introduced, backed by a new European Central Bank holding 15 percent of its reserves in gold.
2000 Astronomers at the Keck Observatory in Hawaii use the giant gold-coated mirrors of the observatory's twin telescopes to produce the most detailed images of Neptune and Uranus ever captured.
Uses of Gold
Of all the minerals mined from the Earth, none is more useful than gold. Its usefulness is derived from a diversity of special properties. Gold conducts electricity, does not tarnish, is very easy to work, can be drawn into wire, can be hammered into thin sheets, alloys with many other metals, can be melted and cast into highly detailed shapes, has a wonderful color and a brilliant luster. Gold is a memorable metal that occupies a special place in the human mind.
When Spanish explorers first arrived in the "New World" they met the native South Americans. These two cultures had been separated by a vast ocean, they had never touched one another, they spoke different languages and lived entirely different lives. Yet they had one thing in common - they both held gold in highest esteem and used it to make some of their most important objects.
Throughout the history of our planet almost every established culture has used gold to symbolize power, beauty, purity and accomplishment. Today we continue to use gold for our most significant objects: wedding rings, Olympic medals, Oscars, Grammys, money, crucifixes and ecclesiastical art. No other substance of the same rarity holds a more visible and prominent place in our society.
Jewelry: The Primary Use of Gold
The production of ornamental objects was probably the first use of gold over 6000 years ago. Gold is found in the pure state, is very easy to work and was probably the first metal used by humans. Today, most of the gold that is newly mined or recycled is used in the manufacture of jewelry. About 78% of the gold consumed each year is used in the manufacture of jewelry.
Special properties of gold make it perfect for manufacturing jewelry. These include: very high luster; desirable yellow color; tarnish resistance; ability to be drawn into wires, hammered into sheets or cast into shapes. These are all properties of an attractive metal that is easily worked into beautiful objects. Another extremely important factor that demands the use of gold as a jewelry metal is tradition. Important objects are expected to be made from gold.
Pure gold is too soft to stand up to the stresses applied to many jewelry items. Craftsmen learned that alloying gold with other metals such as copper, silver, and platinum would increase its durability. Since then most gold used to make jewelry is an alloy of gold with one or more other metals.
The alloys of gold have a lower value per unit of weight than pure gold. A standard of trade known as "karatage" was developed to designate the gold content of these alloys. Pure gold is known as 24 karat gold and is almost always marked with "24K". An alloy that is 50% gold by weight is known as 12 karat gold (12/24ths) and is marked with "12K". An alloy that contains 75% gold by weight is 18 karat (18/24 = 75%) and marked "18K". In general, high karat jewelry is softer and more resistant to tarnish while low karat jewelry is stronger and less resistant to tarnish - especially when in contact with perspiration.
Alloying gold with other metals changes the color of the finished products (see illustration at right). An alloy of 75% gold, 16% silver and 9% copper yields yellow gold. White gold is an alloy of 75% gold, 4% silver, 4% copper and 17% palladium. Other alloys yield pink, green, peach and even black colored metals.
Financial Gold - Coinage, Bullion, Currency Backing
Because gold is highly valued and in very limited supply it has long been used as a medium of exchange or money. The first known use of gold in transactions dates back about 6000 years. Early transactions were done using pieces of gold or pieces of silver. The rarity, usefulness and desirability of gold make it a substance of long term value. Gold works well for this purpose because it has a high value, is durable, portable and easily divisible.
Some early printings of paper money were backed by gold held in safe keeping for every unit of money that was placed in circulation. The United States once used a "gold standard" and maintained a stockpile of gold to back every dollar in circulation. Under this gold standard, any person could present paper currency to the government and demand in exchange an equal value of gold. The gold standard was once used by many nations but it eventually became too cumbersome and is no longer used by any nation.
The gold used as a financial backing for currency was most often held in the form of gold bars, also known as "gold bullion". The use of gold bars kept manufacturing costs to a minimum and allowed convenient handling and storage. Today many governments, individuals and institutions hold investments of gold in the convenient form of bullion.
The first gold coins were minted under the order of King Croesus of Lydia (a region of present-day Turkey) in about 560 BC. Gold coins were commonly used in transactions up through the early 1900's when paper currency became a more common form of exchange. Gold coins were issued in two types of units. Some were denominated in units of currency, such as dollars, while others were issued in standard weights, such as ounces or grams.
Today gold coins are no longer in wide use for financial transactions. However, gold coins issued in specific weights are popular ways for people to purchase and own small volumes of gold for investment. Gold coins are also issued as "commemorative" items. Many people enjoy these commemorative coins because they have both a collectable value and a precious metal value.
Uses of Gold in Electronics
The most important industrial use of gold is in the manufacture of electronics. Solid state electronic devices use very low voltages and currents which are easily interrupted by corrosion or tarnish at the contact points. Gold is the highly efficient conductor that can carry these tiny currents and remain free of corrosion. Electronic components made with gold are highly reliable. Gold is used in connectors, switch and relay contacts, soldered joints, connecting wires and connection strips.
A small amount of gold is used in almost every sophisticated electronic device. This includes: cell phones, calculators, personal digital assistants, global positioning system units and other small electronic devices. Most large electronic appliances such as television sets also contain gold.
One challenge with the use of gold in very small quantities in very small devices is loss of the metal from society. Nearly one billion cell phones are produced each year and most of them contain about fifty cents worth of gold. Their average lifetime is under two years and very few are currently recycled. Although the amount of gold is small in each device, their enormous numbers translate into a lot of unrecycled gold.
Use of Gold in Computers
Gold is used in many places in the standard desktop or laptop computer. The rapid and accurate transmission of digital information through the computer and from one component to another requires an efficient and reliable conductor. Gold meets these requirements better than any other metal. The importance of high quality and reliable performance justifies the high cost.
Edge connectors used to mount microprocessor and memory chips onto the motherboard and the plug-and-socket connectors used to attach cables all contain gold. The gold in these components is generally electroplated onto other metals and alloyed with small amounts of nickel or cobalt to increase durability.
Use of Gold in Dentistry
How would iron work as a dental filling? Not very well... your dentist would need blacksmithing tools, your smile would be rusty a few days after a filling and you would need to get used to the taste of iron. Even at much higher expense, gold is used in dentistry because of its superior performance and aesthetic appeal. Gold alloys are used for fillings, crowns, bridges and orthodontic appliances. Gold is used in dentistry because it is chemically inert, nonallergenic and easy for the dentist to work.
Gold is known to have been used in dentistry as early as 700 B.C. Etruscan "dentists" used gold wire to fasten replacement teeth into the mouths of their patients. Gold was probably used to fill cavities in ancient times;, however there is no documentation or archaeological evidence for this use of gold until a little over 1000 years ago.
Gold was much more generously used in dentistry up until the late 1970's. The sharp run-up of gold prices at that time motivated the development of substitute materials. However, the amount of gold used in dentistry is starting to rise again. Some motivation for this comes from concerns that less inert metals might have an adverse effect on long-term health.
Medical Uses of Gold
Gold is used as a drug to treat a small number of medical conditions. Injections of weak solutions of sodium aurothiomalate or aurothioglucose are sometimes used to treat rheumatoid arthritis. Particles of a radioactive gold isotope are implanted in tissues to serve as a radiation source in the treatment of certain cancers.
Small amounts of gold are used to remedy a condition known as Lagophthalmos, which is an inability of a person to close their eyes completely. This condition is treated by implanting small amounts of gold in the upper eyelid. The implanted gold "weights" the eyelid and the force of gravity helps the eyelid close fully.
Radioactive gold is used in diagnosis. It is injected in a colloidal solution that can be tracked as a beta emitter as it passes through the body. Many surgical instruments, electronic equipment and life-support devices are made using small amounts of gold. Gold is nonreactive in the instruments and is highly reliable in the electronic equipment and life-support devices.
Uses of Gold in Aerospace
If you are going to spend billions of dollars on a vehicle that when launched will travel on a voyage where the possibility of lubrication, maintenance and repair is absolutely zero, then building it with extremely dependable materials is essential. This is exactly why gold is used in hundreds of ways in every space vehicle that NASA launches.
Gold is used in circuitry because it is a dependable conductor and connector. In addition, many parts of every space vehicle are fitted with gold-coated polyester film. This film reflects infrared radiation and helps stabilize the temperature of the spacecraft. Without this coating, dark colored parts of the spacecraft would absorb significant amounts of heat
Gold is also used as a lubricant between mechanical parts. In the vacuum of space, organic lubricants would volatilize and they would be broken down by the intense radiation beyond Earth's atmosphere. Gold has a very low shear strength and thin films of gold between critical moving parts serves as a lubricant - the gold molecules slip past one another under the forces of friction and that provides a lubricant action.
Uses of Gold in Awards and Symbols of Status
What metal is used to make the crown worn by a king? Gold! This metal is selected for use because gold it is THE metal of highest esteem. It would make no sense to make a king's crown out of steel - even though steel is the strongest metal. Gold is chosen for use in a king's crown because it is the metal associated with highest esteem and status.
Gold is associated with many positive qualities. Purity is another quality associated with gold. For this reason, gold is the metal of choice for religious objects. Crosses, communion ware and other religious symbols are almost always made with gold for this reason.
Gold is also used as the first place winner's medal or trophy in almost any type of contest. First place winners at the Olympic Games are given gold medals. The Academy Awards Oscars are gold awards. Music's Grammy Awards are made of gold. All of these important achievements are honored with awards made of gold.
Uses of Gold in Glassmaking
Gold has many uses in the production of glass. The most basic use in glassmaking is that of a pigment. A small amount of gold suspended in the glass when it is annealed produces a rich ruby color.
Gold is also used when making specialty glass for climate controlled buildings and cases. A small amount of gold dispersed within the glass or coated onto the glass surface will reflect solar radiation outward, helping the buildings stay cool in the summer, and reflect internal heat inward, helping them stay warm in winter.
The visor on the helmet of an astronaut's space suit is coated with a very thin film of gold. This thin film reflects much of the very intense solar radiation of space, protecting the astronaut's eyes and skin.
Gold Gilding and Gold Leaf
Gold has the highest malleability of any metal. This enables gold to be beaten into sheets that are only a few millionths of an inch thick. These thin sheets, known as "gold leaf" can be applied over the irregular surfaces of picture frames, molding or furniture.
Gold leaf is also used on the external and internal surfaces of buildings. This provides a durable and corrosion-resistant covering. One of the most eye-catching uses of gold leaf is on the domes of religious buildings and other important structures. The cost of this "roofing material" is very high per square foot; however, the cost of the gold is only a few percent of the total project cost. Most of the cost goes to the labor of highly skilled artisans who apply the gold leaf.
Future Uses of Gold
Gold is too expensive to use by chance. Instead it is used deliberately and only when less expensive substitutes can not be identified. As a result, once a use is found for gold it is rarely abandoned for another metal. This means that the number of uses for gold have been increasing over time.
Most of the ways that gold is used today have been developed only during the last two or three decades. This trend will likely continue. As our society requires more sophisticated and reliable materials our uses for gold will increase. This combination of growing demand, few substitutes and limited supply will cause the value and importance of gold to increase steadily over time. It is truly a metal of the future.
earth-wealth.blogspot.com
Gold
History Of Gold As a Metal
4000 BC Gold is first known to be used in parts of Central and Eastern Europe.
3000 The Egyptians master the arts of beating gold into leaf and alloying gold with other metals to achieve variations in hardness and color. They also develop the ability to cast gold, using the lost-wax technique still used in today's jewelry industry.
The Sumer civilization of southern Iraq uses gold to creat a wide range of jewelry, often using sophisticated and varied styles still worn today.
2500 Gold jewelry is buried in the Tomb of Djer, the king of the First Egyptian Dyanisty, at Abydos, Egypt.
1500 The immense, gold-bearing regions of Nubia make Egypt a wealthy nation, as gold becomes the recognized standard medium of exchange for international trade.
The Shekel, a coin originally weighing 11.3 grams of gold, is used as a standard unit of measure throughout the Middle East. The coin contained a naturally occurring alloy called electrum, which was approximately two-thirds gold and one-third silver.
1352 The young Egyptian King Tutankhamun is interred in a pyramid tomb laden with gold, his remains laid in an extravagant gold anthropoid sarcophagus.
1350 The Babylonians begin to use fire assay to test the purity of gold.
1091 Squares of gold are legalized in China as a form of money.
560 The first coins made purely from gold are minted in Lydia, a kingdom of Asia Minor.
58 Julius Caesar seizes enough gold in Gaul (France) to repay Rome's debts.
50 The Romans issue a gold coin called the Aureus.
600-699 AD The Byzantine Empire resumes gold mining in central Europe and France, an area undeveloped since the fall of the Roman Empire. Artisans of the period produce intricate gold artifacts and icons.
1100 Venice secures its position as the world's leading gold bullion market due to its location astride the trade routes to the east.
1284 Venice introduces the gold Ducat, which soon becomes the most popular coin in the world, and remains so for more than five centuries.
Great Britain issues its first major gold coin, the Florin, which is followed by the Noble, the Angel, the Crown, and the Guinea.
1511 King Ferdinand of Spain sends explorers to the Western Hemisphere with the command to "get gold."
1717 Isaac Newton, Master of the London Mint, sets price of gold that lasts for 200 years.
1787 First US gold coin is struck by Ephraim Brasher, a goldsmith.
1792 The Coinage Act places the young United Sates on a bimetallic silver/gold standard, defining the U.S. Dollar as equivalent to 24.75 grains of fine gold, and 371.25 grains of fine silver.
1803 North Carolina site of first US gold rush. The state supplies all the domestic gold coined for currency by the US Mint in Philadelphia until 1828.
1848 The California gold rush begins when James Marshall finds specks of gold in the water at John Sutter's sawmill near the junction of the American and Sacramento Rivers.
1850 Edward Hammong Hargraves, returning from California, predicts he will find gold in Australia within one week. He discovers gold in New South Wales within one week of landing.
1859 The Comstock Lode of gold and silver is discovered in Nevada. As a result, Nevada is made a state five years later.
1886 George Harrison, while digging stones to build a house, discovers gold in South Africa.
1887 Glasgow doctors, Robert and William Forrest, and chemist John S. MacArthur patent the process for extracting gold from ore using cyanide.
1896 Two prospectors discover gold while fishing in the Klondike River in northern Canada, richer finds were rumored farther south in Alaska's Yukon, spawning the Alaska Gold Rush in 1898 -- the last gold rush of the century.
1900 US adopts the gold standard for its currency.
1903 The Engelhard Corporation introduces an organic medium to print gold on surfaces. First used for decoration, the medium becomes the foundation for microcircuit printing technology.
1922 King Tutankhamun's tomb (1352 BC) opened to reveal a 2,448 lb. gold coffin and hundreds of gold and gold-leafed objects (including the mask pictured at the beginning of this section).
1927 A Medical study in France proves gold to be valuable in treatment of Rheumatoid arthritis.
1933 President Franklin D. Roosevelt bans the export of gold, halts the convertibility of dollar bills into gold, orders US citizens to hand in all the gold they possess and establishes a daily price for gold.
1934 Roosevelt fixes price of gold at $35 per ounce.
1935 Western Electric Alloy #1 (69% gold, 25% silver and 6% platinum) finds universal use in all switching contacts for AT&T telecommunications equipment.
1944 The Bretton Woods agreement sets an international gold exchange standard and creates two new international organizations, the International Monetary Fund (IMF) and the World Band. The new standard sets par values for currencies in terms of gold and obligates member countries to convert foreign offical holdings of their currencies into gold at these par values.
1947 The first transistor, the building block for electronics, is assembled at AT&T Bell Laboratories. The device uses gold contacts pressed into a germanium surface.
1960 The laser is invented using gold-coated mirrors to maximize infrared reflection.
1961 Modern-day mining begins in Nevada's Carlin Trend, ultimately making Nevada the nation's largest gold-mining state.
1968 Intel introduces a microchip with 1,024 transistors connected by gold circuits.
On March 15, central banks give up fixed price of gold at $35 per troy ounce and let it free float.
1969 Gold coated visors protect the astronauts' eyes from searing sunlight on the moon (Apollo 11 moon landing).
1970 The charged coupled device is invented, using gold to collect electrons generated by light, eventually used in hundreds of military and civilian devices, including video cameras.
1971 The colloidal gold marker system is introduced by Amersham Corporation of Illinois. Tiny spheres of gold are used in health research laboratories worldwide to mark or tag specific proteins to reveal their function in the human body for the treatment of disease.
1973 The U.S. Dollar is removed from gold standard, and gold prices are allowed to float free. By June, the market for gold in London reaches more than $120 per ounce.
1974 On December 31, US government ends its ban on individual ownership of gold.
1976 The Gold Institute is established in Washington, D.C., to promote the common interests of the gold industry by providing statistical data and other relevant information to its members, the media, government, and the public.
1980 Gold reaches intra-day historic high price of $870 on January 21 in New York.
1986 Gold-coated compact discs are introduced.
1987 Airbags are introduced for cars, using gold contacts for reliability.
1996 The Mars Global Surveyor is launched with an on-board gold-coated parabolic telescope-mirror that will generate a detailed map of the entire Martian surface over a two-year period.
1997 Congress passes Taxpayers Relief Act, allowing US Individual Retirement Account holders to buy gold bullion coins and bars for their accounts as long as they are of a fineness equal to, or exceeding, 99.5 percent gold.
1999 The Euro, a pan-European currency, is introduced, backed by a new European Central Bank holding 15 percent of its reserves in gold.
2000 Astronomers at the Keck Observatory in Hawaii use the giant gold-coated mirrors of the observatory's twin telescopes to produce the most detailed images of Neptune and Uranus ever captured.
Uses of Gold
Of all the minerals mined from the Earth, none is more useful than gold. Its usefulness is derived from a diversity of special properties. Gold conducts electricity, does not tarnish, is very easy to work, can be drawn into wire, can be hammered into thin sheets, alloys with many other metals, can be melted and cast into highly detailed shapes, has a wonderful color and a brilliant luster. Gold is a memorable metal that occupies a special place in the human mind.
When Spanish explorers first arrived in the "New World" they met the native South Americans. These two cultures had been separated by a vast ocean, they had never touched one another, they spoke different languages and lived entirely different lives. Yet they had one thing in common - they both held gold in highest esteem and used it to make some of their most important objects.
Throughout the history of our planet almost every established culture has used gold to symbolize power, beauty, purity and accomplishment. Today we continue to use gold for our most significant objects: wedding rings, Olympic medals, Oscars, Grammys, money, crucifixes and ecclesiastical art. No other substance of the same rarity holds a more visible and prominent place in our society.
Jewelry: The Primary Use of Gold
The production of ornamental objects was probably the first use of gold over 6000 years ago. Gold is found in the pure state, is very easy to work and was probably the first metal used by humans. Today, most of the gold that is newly mined or recycled is used in the manufacture of jewelry. About 78% of the gold consumed each year is used in the manufacture of jewelry.
Special properties of gold make it perfect for manufacturing jewelry. These include: very high luster; desirable yellow color; tarnish resistance; ability to be drawn into wires, hammered into sheets or cast into shapes. These are all properties of an attractive metal that is easily worked into beautiful objects. Another extremely important factor that demands the use of gold as a jewelry metal is tradition. Important objects are expected to be made from gold.
Pure gold is too soft to stand up to the stresses applied to many jewelry items. Craftsmen learned that alloying gold with other metals such as copper, silver, and platinum would increase its durability. Since then most gold used to make jewelry is an alloy of gold with one or more other metals.
The alloys of gold have a lower value per unit of weight than pure gold. A standard of trade known as "karatage" was developed to designate the gold content of these alloys. Pure gold is known as 24 karat gold and is almost always marked with "24K". An alloy that is 50% gold by weight is known as 12 karat gold (12/24ths) and is marked with "12K". An alloy that contains 75% gold by weight is 18 karat (18/24 = 75%) and marked "18K". In general, high karat jewelry is softer and more resistant to tarnish while low karat jewelry is stronger and less resistant to tarnish - especially when in contact with perspiration.
Alloying gold with other metals changes the color of the finished products (see illustration at right). An alloy of 75% gold, 16% silver and 9% copper yields yellow gold. White gold is an alloy of 75% gold, 4% silver, 4% copper and 17% palladium. Other alloys yield pink, green, peach and even black colored metals.
Financial Gold - Coinage, Bullion, Currency Backing
Because gold is highly valued and in very limited supply it has long been used as a medium of exchange or money. The first known use of gold in transactions dates back about 6000 years. Early transactions were done using pieces of gold or pieces of silver. The rarity, usefulness and desirability of gold make it a substance of long term value. Gold works well for this purpose because it has a high value, is durable, portable and easily divisible.
Some early printings of paper money were backed by gold held in safe keeping for every unit of money that was placed in circulation. The United States once used a "gold standard" and maintained a stockpile of gold to back every dollar in circulation. Under this gold standard, any person could present paper currency to the government and demand in exchange an equal value of gold. The gold standard was once used by many nations but it eventually became too cumbersome and is no longer used by any nation.
The gold used as a financial backing for currency was most often held in the form of gold bars, also known as "gold bullion". The use of gold bars kept manufacturing costs to a minimum and allowed convenient handling and storage. Today many governments, individuals and institutions hold investments of gold in the convenient form of bullion.
The first gold coins were minted under the order of King Croesus of Lydia (a region of present-day Turkey) in about 560 BC. Gold coins were commonly used in transactions up through the early 1900's when paper currency became a more common form of exchange. Gold coins were issued in two types of units. Some were denominated in units of currency, such as dollars, while others were issued in standard weights, such as ounces or grams.
Today gold coins are no longer in wide use for financial transactions. However, gold coins issued in specific weights are popular ways for people to purchase and own small volumes of gold for investment. Gold coins are also issued as "commemorative" items. Many people enjoy these commemorative coins because they have both a collectable value and a precious metal value.
Uses of Gold in Electronics
The most important industrial use of gold is in the manufacture of electronics. Solid state electronic devices use very low voltages and currents which are easily interrupted by corrosion or tarnish at the contact points. Gold is the highly efficient conductor that can carry these tiny currents and remain free of corrosion. Electronic components made with gold are highly reliable. Gold is used in connectors, switch and relay contacts, soldered joints, connecting wires and connection strips.
A small amount of gold is used in almost every sophisticated electronic device. This includes: cell phones, calculators, personal digital assistants, global positioning system units and other small electronic devices. Most large electronic appliances such as television sets also contain gold.
One challenge with the use of gold in very small quantities in very small devices is loss of the metal from society. Nearly one billion cell phones are produced each year and most of them contain about fifty cents worth of gold. Their average lifetime is under two years and very few are currently recycled. Although the amount of gold is small in each device, their enormous numbers translate into a lot of unrecycled gold.
Use of Gold in Computers
Gold is used in many places in the standard desktop or laptop computer. The rapid and accurate transmission of digital information through the computer and from one component to another requires an efficient and reliable conductor. Gold meets these requirements better than any other metal. The importance of high quality and reliable performance justifies the high cost.
Edge connectors used to mount microprocessor and memory chips onto the motherboard and the plug-and-socket connectors used to attach cables all contain gold. The gold in these components is generally electroplated onto other metals and alloyed with small amounts of nickel or cobalt to increase durability.
Use of Gold in Dentistry
How would iron work as a dental filling? Not very well... your dentist would need blacksmithing tools, your smile would be rusty a few days after a filling and you would need to get used to the taste of iron. Even at much higher expense, gold is used in dentistry because of its superior performance and aesthetic appeal. Gold alloys are used for fillings, crowns, bridges and orthodontic appliances. Gold is used in dentistry because it is chemically inert, nonallergenic and easy for the dentist to work.
Gold is known to have been used in dentistry as early as 700 B.C. Etruscan "dentists" used gold wire to fasten replacement teeth into the mouths of their patients. Gold was probably used to fill cavities in ancient times;, however there is no documentation or archaeological evidence for this use of gold until a little over 1000 years ago.
Gold was much more generously used in dentistry up until the late 1970's. The sharp run-up of gold prices at that time motivated the development of substitute materials. However, the amount of gold used in dentistry is starting to rise again. Some motivation for this comes from concerns that less inert metals might have an adverse effect on long-term health.
Medical Uses of Gold
Gold is used as a drug to treat a small number of medical conditions. Injections of weak solutions of sodium aurothiomalate or aurothioglucose are sometimes used to treat rheumatoid arthritis. Particles of a radioactive gold isotope are implanted in tissues to serve as a radiation source in the treatment of certain cancers.
Small amounts of gold are used to remedy a condition known as Lagophthalmos, which is an inability of a person to close their eyes completely. This condition is treated by implanting small amounts of gold in the upper eyelid. The implanted gold "weights" the eyelid and the force of gravity helps the eyelid close fully.
Radioactive gold is used in diagnosis. It is injected in a colloidal solution that can be tracked as a beta emitter as it passes through the body. Many surgical instruments, electronic equipment and life-support devices are made using small amounts of gold. Gold is nonreactive in the instruments and is highly reliable in the electronic equipment and life-support devices.
Uses of Gold in Aerospace
If you are going to spend billions of dollars on a vehicle that when launched will travel on a voyage where the possibility of lubrication, maintenance and repair is absolutely zero, then building it with extremely dependable materials is essential. This is exactly why gold is used in hundreds of ways in every space vehicle that NASA launches.
Gold is used in circuitry because it is a dependable conductor and connector. In addition, many parts of every space vehicle are fitted with gold-coated polyester film. This film reflects infrared radiation and helps stabilize the temperature of the spacecraft. Without this coating, dark colored parts of the spacecraft would absorb significant amounts of heat
Gold is also used as a lubricant between mechanical parts. In the vacuum of space, organic lubricants would volatilize and they would be broken down by the intense radiation beyond Earth's atmosphere. Gold has a very low shear strength and thin films of gold between critical moving parts serves as a lubricant - the gold molecules slip past one another under the forces of friction and that provides a lubricant action.
Uses of Gold in Awards and Symbols of Status
What metal is used to make the crown worn by a king? Gold! This metal is selected for use because gold it is THE metal of highest esteem. It would make no sense to make a king's crown out of steel - even though steel is the strongest metal. Gold is chosen for use in a king's crown because it is the metal associated with highest esteem and status.
Gold is associated with many positive qualities. Purity is another quality associated with gold. For this reason, gold is the metal of choice for religious objects. Crosses, communion ware and other religious symbols are almost always made with gold for this reason.
Gold is also used as the first place winner's medal or trophy in almost any type of contest. First place winners at the Olympic Games are given gold medals. The Academy Awards Oscars are gold awards. Music's Grammy Awards are made of gold. All of these important achievements are honored with awards made of gold.
Uses of Gold in Glassmaking
Gold has many uses in the production of glass. The most basic use in glassmaking is that of a pigment. A small amount of gold suspended in the glass when it is annealed produces a rich ruby color.
Gold is also used when making specialty glass for climate controlled buildings and cases. A small amount of gold dispersed within the glass or coated onto the glass surface will reflect solar radiation outward, helping the buildings stay cool in the summer, and reflect internal heat inward, helping them stay warm in winter.
The visor on the helmet of an astronaut's space suit is coated with a very thin film of gold. This thin film reflects much of the very intense solar radiation of space, protecting the astronaut's eyes and skin.
Gold Gilding and Gold Leaf
Gold has the highest malleability of any metal. This enables gold to be beaten into sheets that are only a few millionths of an inch thick. These thin sheets, known as "gold leaf" can be applied over the irregular surfaces of picture frames, molding or furniture.
Gold leaf is also used on the external and internal surfaces of buildings. This provides a durable and corrosion-resistant covering. One of the most eye-catching uses of gold leaf is on the domes of religious buildings and other important structures. The cost of this "roofing material" is very high per square foot; however, the cost of the gold is only a few percent of the total project cost. Most of the cost goes to the labor of highly skilled artisans who apply the gold leaf.
Future Uses of Gold
Gold is too expensive to use by chance. Instead it is used deliberately and only when less expensive substitutes can not be identified. As a result, once a use is found for gold it is rarely abandoned for another metal. This means that the number of uses for gold have been increasing over time.
Most of the ways that gold is used today have been developed only during the last two or three decades. This trend will likely continue. As our society requires more sophisticated and reliable materials our uses for gold will increase. This combination of growing demand, few substitutes and limited supply will cause the value and importance of gold to increase steadily over time. It is truly a metal of the future.
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