Right from the beginning of the oldest civilization, gold has been used for a myriad of applications. Its occurrence is in the form of grains in rocks, veins and alluvial deposits. Out of all the metals which are known to man, gold possess the highest degree of ductility and malleability, while being dense, soft and shiny at the same time. Apart from these, properties which make gold find numerous applications in industries, are its high resistance to corrosion, superior electrical conductivity, infrared reflectivity, and thermal conductivity.

Applications of Gold

# Well, it is known to all that the primary use of gold is associated to jewelry. About 78% of the gold consumed each year goes in the manufacture of different jewelry products. So talking about uses of this metal in ancient times, it was employed in the production of ornamental objects, and this fact dates back to about 6000 years. Again, why is gold popular in the manufacture of jewelry? It is because of its properties of being lustrous, bearing a desirable yellow color, being tarnish resistance, and most important of all, being incredibly high in malleability and ductility. A famous example is the gold foil which is placed in Toi museum, Japan. This foil is about 0.5 square meter and it was formed by hammering a gold nugget of a mere 5 mm in diameter. So, you can see how far this metal can expand.

# Not only in making of ornaments, gold, being a highly valued item, was used as a medium of exchange or money. This use of gold in transaction first occurred about 6000 years ago. It was in about 560 BC when the first gold coins were minted. This occurred under the reign of King Croesus of Lydia. Pieces of gold were used for transaction purposes until the 1900s, when paper currency came into use.

Coming to the industrial applications of gold, here's what you can refer to.

# Solid state electronic devices work on extremely low voltages and currents. However, the contact points are prone to corrosion and may get easily tarnished. These limitations might interrupt the proper functioning of the devices. This is overcome by the using gold, which not only conducts electricity, but also keeps the contacts from getting corroded. This is the reason electronic devices which have gold in their making, are more reliable than those who don't. Gold finds its application in electronics for contacts, switches, relays, soldered joints, connecting wires and connection strips. Television sets, cell phones, calculators, personal digital assistants, global positioning system units and other small electronic devices are products which have gold as one of their building components.

# Most of us are aware of the catalytic converter in vehicles. The job of this device is to convert the toxic emissions of a vehicle into non-toxic ones when it is emitted into the atmosphere. The main components of this device comprise a reduction catalyst and an oxidation catalyst. Given the complex nature of contaminating particles, and extreme temperatures, the catalysts that are used here must have superior degree of robustness and durability. And these properties are possessed by precious metals. So the role of the reduction catalyst is played by the metal Rhodium (Rh), and Palladium (Pd) takes the job of oxidation. Platinum (Pt) is also used, for both reduction and oxidation. Given the high price of these metals, some of newest catalytic converters have the traditional catalysts mixed with gold. This is because gold is cheaper than the other precious metals, and can also increase oxidation thus, making the process even more efficient.

# The desktops or laptops which we use everyday, also use gold as an efficient and reliable conductor. Unlike other metals, gold is more efficient in transmitting rapid and accurate digital information from one component to the other in such devices. The edge connectors and plug-and-socket connectors contain gold which is alloyed with other metals.

# In places like North America, gold-coated glasses are used for several climate controlled buildings and cases. As these glasses are coated with gold, they reflect solar radiation outward, thus, bringing down the cooling and heating costs by a large extent. Thin sheets known as gold leaf, are used on the external and internal surfaces of buildings. The Royal Bank Plaza in Toronto, Canada is a living example of how extremely useful gold can be when it comes to warding off heat radiation. The building has 14,000 windows, and each of them has a thin coating of 24-carat gold leaf, amounting to 70,875 grams of gold. And all this to insulate the building, keeping the structure cool in summer, and warm in winter.

# Nanotechnology is one of the major breakthroughs in the field of science. Even here, gold has not been left behind, given its reliability that scores impressively higher than that of other elements. Apart from this, future technologies like those which are aimed at water purification, mercury control, and control of diesel emission have the prospect of using gold in their projects, due to its unique chemical and metallurgical properties.

# Coming to uses of this expensive metal in medical science, dental filling also utilizes it efficiently. Dental filling using gold, is although, a pricey affair, the metal's superior performance and aesthetic look and appeal are worth the investment. Gold is an inert metal, i.e., it does not react with any other substance. Apart from this, it is non-allergenic and provides ease to dentists to work with it. Considering these benefits, the metal is used in fillings, crowns, bridges and orthodontic appliances. However, pure gold is far from being used, as it is too soft to withstand any wear and tear. That is why it is alloyed with other metals. Medical conditions such as rheumatoid arthritis, lagophthalmos (abnormal condition in which an eye cannot close completely), liver and ear diseases, anergia, etc. also have the implementation of gold in their treatment.

# Gold being a reliable connector and conductor, finds numerous application in almost all space vehicles which are manufactured by NASA. If you can remember what was mentioned at the beginning of this article, gold has the property of being a perfect reflector of infrared (heat) radiation. In space programs, gold sheets are employed as radiation shield, as they can deflect the burning heat of the sun. The famous US Columbia space shuttle was manufactured using gold in its brazing alloys, fuel cell fabrication, coated plastic films and electrical contacts. How much of gold was used? More than 40.7 kg.

Not to mention the use of gold in awards and as a symbol of high status. Even in food and drinks and in cosmetics and beauty applications, gold finds its usefulness and efficiency. The use of this metal has been increasing over time, and as the civilization is growing in leaps and bounds, there are high chances that gold will encompass more applications. And, then I will be coming up with perhaps, more information and data regarding the myriad uses of this truly invaluable metal, gold!