The Many Uses of Gold
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Cameo in Gold Setting
©iStockphoto.com/Angelo Marcantonio
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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
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Gold ring with colored stone.
©iStockphoto.com/Krzysztof Gorski
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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.
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Gold rings of different color.
©iStockphoto.com/Martin McCarthy
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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
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Gold bullion. USDOJ Image.
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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.
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United States Gold Coins
©iStockphoto.com / Donald Swartz
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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 because 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
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Cell Phone
©iStockphoto.com
Matjaz Boncina
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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
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Gold in a computer memory chip
©iStockphoto.com / Teresa Azevedo
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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
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A crown made from dental gold alloy.
©iStockphoto.com / choicegraphx
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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
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Gold is used in surgical instruments
©iStockphoto.com / atbaei
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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
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Gold is used in satellite components
©iStockphoto.com / pete stopher
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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 zero, then
building it with materials that are absolutely dependable is critical.
This is exactly why gold is used in every space vehicle that NASA
launches.
Gold is used in circuitry because it is a dependable conductor and
connector. Critical part of space vehicles are fitted with gold-coated
polyester film. This film reflects infrared radiation and helps
stabilize the temperature of the spacecraft.
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. Like
graphite, gold has a very low shear strength and thin films of gold
between critical moving parts are often used as a lubricant.
Uses of Gold in Awards and Symbols of Status
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Gold Medal
©iStockphoto.com
Olivier Blondeau
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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
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Gold is used in specialty building glass
©iStockphoto.com / Cezar Serbanescu
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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
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Gold dome of a church
©iStockphoto.com / Constantine Vishnevsky
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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
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Prague Astronomical Clock
©iStockphoto.com / Kelly Borsheim
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Gold is too expensive to use by chance. Instead it is
used deliberately and only when less expensive substitutes can 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
