Among the metals, gold may be the most challenging metal which has very unique properties that made it very precious throughout history. Besides the historical value, gold is also very valuable for different applications today.
Also, we would like to give the most general viewpoint about gold by touching from different fields. And also, you can find detailed information about gold. The information and commentaries about gold are like below in this article.
- What is gold? Definitions of a gold element with the viewpoint of different fields.
- Physical and mechanical properties of gold element
- The short history of gold element, how people used it, and how they trade.
- The production and mining of gold elements. Alloying of the gold element.
- In which applications that we use gold in today’s technology.
- The production rates of gold in the world.
- Prices and investments of gold elements in the world.
- FAQs about the gold element.
What is Gold?
We can answer this general question about gold in different ways. Because it is a very open-ended question about gold. In general, we give the answer to this question in terms of chemistry.
Furthermore, gold is a metallic element that has the atomic number 79 in the periodic table. The symbol is ‘Au’ and which does not resemble its name. The symbol ‘Au’ came from its name in Latin ‘aurum’.
And also, gold is classified as a transition metal. The place of the gold element in the periodical table; group 11, period 6, and block d respectively. The atomic radius of the gold is 135pm and the Covalent bonding radius is 144pm. The Van der Waals radius of the gold element is 166pm.
These are the most general information about gold elements. But in general, these properties and features of gold are not the parameters that make the gold metal special from other metals. But first of all, we need to take a look at the historical importance of the gold element.
History of the Gold
In general, different cultures used Gold as trappings. So, the first historical findings of the Gold date back to 5000 BC that Egyptian emperors used as a coinage. Also, coinage of the Gold is one of the most common purposes that Gold is used in. Aztec and Inka civilizations used Gold as jewelry and there are findings of the use of Gold dating back to 2000 BC in South America. Greeks, Sumerians, Persians, Macedon, and Assyrians also used Gold as the main coinage and trapping metal in history.
With the advance of history, gold became more popular and more valuable for human beings. First of all, governments used gold as the main investment tool in the modern economy and money printing is dependent on the gold reserves. Also, we use gold in different electronic technologies that make gold much more valuable metal. So, various historical and technological properties make gold a very valuable metal.
Physical and Mechanical Properties of Gold Element
The pure gold element is a malleable and shiny metal. The color of the pure gold is reddish yellow. This highly ductile metal that we can shape easily into different forms. This capability gives its important ability to shape into different shapes in jewelry. We make lots of types of necklaces, rings, and other trappings from pure gold.
- Density: The density of the gold element is 19,3 g/cm³ which is very heavy if we compare with other metals and materials.
- Melting and Boiling Temperatures: The melting point of the gold is 1064,18 °C and the boiling temperature of the gold element is 2856 °C.
- Mohs Hardness: The Mohs hardness value of the gold element is 2.5.
- Vickers Hardness: The Vickers hardness of the gold element is 216 MPa.
- Brinell Hardness: The Brinell hardness of the gold element is 2450 MPa.
- Electrical Resistivity: The electrical resistivity of the gold element is 22,14 nΩ·m at 20°C which is very low if we compare with other conductive metals. Because of this reason, we used gold in such electronic applications where very good electrical conductivity is important.
The Thermal Properties
- Thermal Conductivity: Thermal conductivity of the gold element is 318 W/(m·K) which is also very high if we compare with other elements. But because of the prices of the gold element, there are no common applications that the thermal conductivity of the gold element that we use.
- The heat of Fusion: The heat of fusion of the pure gold element is 12,55 kJ/mol.
- The heat of Evaporation: The heat of evaporation of the gold element is 324 kJ/mol.
- Electronegativity: The electronegativity of the gold element is 2,54 according to the Pauling scale.
These are the general physical and mechanical characteristics of the gold element which makes this element very special among others. The most important characteristic of the gold element is very low electrical resistivity.
How to Produce Gold?
Firstly, we mine the gold from natural sources in two types; goıld ores that contain metallic gold and gold ores that contain chemical compounds of gold.
Also, the containment of the gold element is not complex like other metallic elements. A big percentage of the gold ores are the gold ore that contains metallic gold. From these types of ores, we obtain small quartz pieces. And in grinding machines, these little quartz pieces are converted into a slurry. In this slurry, gold is compounded colloidally. A special technique called gold smashing is used to decompose this colloidal gold. With this technique, we increase the concentration of the slurry.
After that, we mix this slurry with the diluted sodium cyanide which creates a complex chemical compound. The chemical reaction takes place;
4 NaAu(CN)2 + 4 NaOH → 4 Au + 8 NaCN + 2 H2O + O2
With the use of metallic Zinc, gold is precipitated. So, Gold is decompounded like in this chemical reaction;
2 Na + 2 Au(CN)2 + Zn → 2 Au + Na2Zn(CN)4
The other materials and elements in this composition are decomposed by the Kal method. The silver is decomposed by sulphuric acid and pure gold remains.
Practical and Engineering Applications That We Use the Gold Element
Except for the gold’s investment value and valuable trading item in the economy, there are lots of technological applications that we use the gold element.
Electrical and Electronic Applications of Gold
After the silver and copper, the electrical conductivity of the gold element is the highest among other metals. And also gold is chemically inert. Because of these two features, we use gold in the coating of the connections, terminals, printed circuits, transistors, and semiconductor systems.
Gold has another very special feature that it can reflect nearly 98% of harmful radiations and infrared rays. Because of it, they use thin gold coatings on the astronaut suits and reflectors of satellites.
Coating Applications of Gold
They use Gold element in coating applications because of the inertness to chemical reactions. In general, gold is found in +1 and +3 valences in its chemical reactions and chemical compounds. Because of this reason, they can reduce the gold to a pure form from its chemical compounds.
Also, they use gold in the coating industry where they compound it with potassium cyanide and sodium.
The AuCl3 is soluble in water and they can use this chemical compound of gold in photography.
The AuBr3 is soluble in alcohol and ether and they use this compound of the gold element in some chemical analyses.
In gilding applications and gilding coating techniques, Au(OH)3 which is also called gold hydroxide is used.
Alloys of Gold Element
Above all, there are different alloys of the gold element.
- Gold-Silver Alloy: In general, they use gold-silver alloys in the jewelry industry.
- Gold-Nickel Alloy: They use Gold-Nickel alloy in the production of white gold. In this alloy, there is 80% of gold, 16% of nickel, and 1% copper.
- Gold-Copper Alloy: They use gold copper alloys in the coinage.
Gold Content and Caratages
In jewelry, gold content and gold carats are important terms. So, according to the gold content in the commercial golds, they define carats.
24 Carats of Gold
We call the 100% pure gold 24 carats of gold. But in nature, there is not 100% of gold and the purest gold is 99.99% of purity.
22 Carats of Gold
The 22 carats of gold contain 91.65 pure gold inside it. The remaining percentage is completed with other metals such as silver or copper.
18 Carats of Gold
The 18 carats of gold include 75.14% of pure gold elements inside it.
14 Carats of Gold
The 14 carats of gold contain around 58.55 pure gold elements.
If the complementary metal is silver, they obtain yellow gold which they use in the jewelry sector. Also, if they use the copper as a complementary metal, reddish color of gold is obtained.
White gold is generally produced from 9k and 10k of gold which contains the metal compositions to give the color white.
Gold Production in the World
Gold is a very important element in the economics of the world. Lots of economic situations between the countries are dependent on gold. So, gold reserves are an important indicator of the economical power of the countries. Because of it, gold production is a very important sector around the world. Because of these reasons, gold production gives a rotation to the world economic situation.
If we take a look at the biggest gold producer countries, will see that China is the biggest one. Gold production in China is around 400 tonnes. The second-biggest gold producer country is Australia which is 312 tonnes. If we take a look at the gold production of other countries;
- China: 400 tonnes
- Australia: 312 tonnes
- Russia: 281 tonnes
- The US: 253 tonnes
- Canada: 193 tonnes
- Indonesia: 190 tonnes
- Peru: 155 tonnes
- South Africa: 123 tonnes
- Mexico: 121 tonnes
- Ghana: 101 tonnes
As you see from the list above, there is no direct relation between the wealth of countries and gold production. At the top of the list, are the wealthiest countries. But other wealthy countries such as Japan and Germany are not on this list.
Ghana is not a wealthy country compared with other ones on the list. But she takes 10th place in the gold production. Maybe colonialism is still going on in 2022…
Countries with the Most Gold Stocks
Maybe there is no direct relationship between the gold production of the countries and the wealth of these countries. But there is a direct relationship between the gold stock of the countries and the economic power of countries. The wealth of the countries is dependent on different factors such as population. For example, China is the second biggest economic power but the income per capita is not high as other wealthy countries. This is because the population is very high.
If we take a look a the biggest gold holder countries in the world, The United States comes in the first place. The total gold stock of the US is 8135 tonnes. The second-biggest gold holder country is Germany which has 3372 tonnes of gold stocks. The third one is the IMF which has 2814 tonnes of gold reserves. The situation of the other countries;
- The US: 8135 tonnes
- Germany: 3372 tonnes
- IMF: 2814 tonnes
- Italy: 2451 tonnes
- France: 2436 tonnes
- Russia: 1890 tonnes
- China: 1842 tonnes
- Switzerland: 1040 tonnes
- Japan: 756 tonnes
- The Netherlands: 612 tonnes
As you see above, there is no direct relationship between the gold production and the gold reserves of countries. For example, Germany is the second biggest gold holder country which is not on the biggest gold producers list. So we can say that gold is the indicator of economical power but not the direct source of economical power or wealth of countries.
Gold Prices and Investments in Golds In the World
Unlike other metals, gold is a primary investment tool for people and countries. So gold prices are directly related to investor behaviors.
Factors that are Affecting the Gold Prices
Also, other important factors affect the gold prices in the world. One of the other factors is the economical situation of the world. Gold prices are directly related to the trades of other goods between countries.
Unlike other metals, the price of gold is not related to the production of gold or the demand for gold from manufacturing industries. A very big amount of gold today is used as an investment tool. So, we need to examine the gold prices from the viewpoint of investment.
Prices of Gold
If we take a look at the price chart of the gold, there is an increment through the years, unlike other metals. This is because the use gold as an investment tool and investment tools are always valuable. This is because the production rate of the gold element in the world is limited compared to the money printing in the world. The money printing rate is bigger than the gold production which makes the prices upward direction.
There is a sharp increment in gold prices around 2008 which is probably about the 2008 World economical crisis. Also a sharp increment after 2018-2019 because of the Covid-19 lockdowns. During the Covid-19 lockdowns, the US government printed lots of US dollars and the money printing in the Covid-19 process was in a historical acceleration. So, the sharp increment in gold prices is logical.
Also, Trump’s economical war against China can be a very big factor in the increment of the gold prices around the 2020s. Lots of kinds of investors are investing their money in gold because of this fragile economical situation in the world.
As you understand that the prices of gold are generally affected by the economical situation of the world and directly affected by the economical environments other than other factors such as production, logistics, and demand of gold by other countries and industries.
As you understand from the information and commentaries above, the chemical and mechanical properties of a gold element are very important. There are lots of practical applications of gold besides its value in the investment.
We tried to give the most general viewpoint of gold in this article. We took a look at the gold element from chemistry, production and manufacturing, and economic viewpoints.
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FAQs About the Gold
There are no additional elements in gold. Gold is an element by itself. But there are alloys of gold in which they add other elements inside the gold for different purposes. Copper and silver are the most known elements that are alloyed with gold.
The specialty of gold comes from its economical and investment value of it. Gold is a rare metal and the production rate of gold is limited if we compare with other metals. Because of it, gold is special to other materials.
The biggest gold holder country is the US. But in the central bank reserves, the biggest gold reserves are in Australia.
The total estimation of gold reserves is 50.000 tonnes and around 190.000 tonnes of gold that they mined in the world. We can say that the prices of gold will increase with the ongoing years.
Gold is a special metal that is not rusted or tarnished in the atmosphere, unlike other metals.