INTRODUCTION

Gold is a chemical element with the symbol Au, its atomic number is 79. Gold is the most precious and rare metal. It is the densest metal among all the metals. In its purest form, it is a bright, slightly orange-yellow, dense, soft, malleable and ductile metal. Chemically, gold is a transition metal, 11th group element and one of the noble metals. It is one of the least reactive metals, and being the 2nd lowest in the reactivity series. It is solid under standard conditions.

 Like copper, gold has a single s electron outside a completed d shell, but, in spite of the similarity in electronic structures and ionization energies, there are few close resemblances between gold on the one hand and copper on the other

Gold has been used in jewelry, coinage and other works of arts.

Because of its unique qualities, gold has been one of the best materials that is universally accepted for the exchange of goods and services. Gold has occasionally played an important role as a high-denomination currency, although silver was generally the standard medium of payments in the world’s trading system. Gold also has significant cultural and economic importance across the globe.

PROPERTIES

Gold is a type of precious metal that can be used by every human being and also for various other purposes in different industries.
Here’s a breakdown of its key physical properties in an easy-to-understand way:

Chemical properties of Gold

Gold is a rare, precious and costly metal. It exhibits different physical and chemical properties.

Physical properties of Gold

1. This high density of gold 19.32 g/cm3 at 20°C (room temperature) is one of the reasons that gold is often associated with wealth and value, as it’s much denser than most other metals.

Comparison: Gold is almost twice as dense as Lead, making it easy to identify by weight.

1. Gold is a distinctly yellow metal with reddish hue, it has metallic luster, also it reflects 80% of visible light.  It is highly reflective in its pure state, creating a bright, glossy appearance.
2. Gold is soft and malleable, which is why pure gold is often alloyed with other metals like copper or silver to improve its hardness for practical uses such as jewelry or coinage.

Gold’s low hardness means it can be easily hammered into thin sheets (gold leaf) or drawn into fine wires, making it highly valued in art and decoration.

1. Gold is highly malleable and ductile and can be hammered into thin sheets and drawn into wires. One ounce of gold can be stretched into a thread that is over 50 miles long without breaking. 
2. Gold is an excellent conductor of electricity, it resists corrosion tarnishing and oxidation making it ideal for use in electronics and electronic connections.
3. Gold is a good conductor of heat, which makes it useful in heat sensitive applications, such as space equipment and high performance electronics.
4. Gold is non-magnetic, making it useful in scientific and industrial applications.
5. One of gold’s most notable physical properties is its exceptional corrosion resistance. It does not tarnish, rust, or corrode over time, even when exposed to air, water, or most chemicals. This property makes it extremely durable in a variety of environments, such as in jewelry, coins, and medical applications.

Occurrence

Gold has been a symbol of wealth, power, and divine connection since ancient times. The Egyptians were some of the first to extensively mine gold, using it for everything from jewelry to ceremonial burial items. The famous burial mask of Pharaoh Tutankhamun, made from solid gold, exemplifies the luxurious use of gold in ancient cultures.

Throughout history, gold has served as a medium of exchange. The gold standard was an economic system in which the value of a country’s currency was directly linked to a specific quantity of gold. This system was used by many countries until the mid-20th century, after which fiat currency (backed by governments rather than precious metals) became the norm.

Gold is relatively a rare element in the earth’s crust which does not occur naturally in large amounts.

Natural Occurence of Gold

Gold is the most rare and precious metal, gold occurs naturally in earth’s crust in two primary forms native gold and gold ores.

  Native gold:

1. Native refers to gold occurring in its pure metallic form without combining with other elements.
2. In rocks it is found in the form of nuggets, veins and or flakes
3. Native compounds are made up of 99% gold, with small amounts of other elements like silver, platinum, and copper and sometimes present  as impurities.

Gold Ores

1. Gold ores are rocks that contain significant concentrations of gold that can be extracted through mining. The gold is usually found in the form of gold compounds combined with other elements such as sulfides (e.g. pyrite, arsenopyrite) oxides.
2. These ores must undergo various refining processes (e.g., cyanidation, smelting) to extract the gold.

Geological condition for Gold formation

Gold is not uniformly distributed across the Earth’s surface, and its occurrence is highly influenced by geological processes. These processes can concentrate gold in certain areas, creating large deposits that are economically viable for mining. Some of the key geological settings where gold is found include:

1. Primary Gold deposits
2. Placer Deposits
3. Hydrothermal Gold Deposits

Primary Gold Deposits

Gold is locked in quartz, veins and other types of rock formations in primary gold deposits. Primary gold deposits also known as lode deposits.

These deposits form in areas of intense tectonic plates, where the movement of Earth’s plates allows gold-bearing fluids to rise and deposit gold in cracks in the surrounding rock.

Lode gold deposits are often located in mountainous regions or along fault lines.

Placer Gold Deposits

Placer deposits are concentrations of gold that have been transported by water from their original source (e.g., lode deposits) and accumulated in riverbeds, stream beds, and other alluvial deposits.

Gold is heavier than most other minerals, so it tends to settle and accumulate in areas where water slows down, such as the bottom of rivers or in sandbars.

Over time, gold particles can be concentrated in these deposits, making them a major source of gold mining.

Hydrothermal gold deposits

Hydrothermal deposits occur when gold is deposited by hot, mineral-rich fluids (called hydrothermal fluids) that seep through fractures in the Earth’s crust.

• These fluids carry dissolved gold, which precipitates out as gold ore when they cool or encounter a chemical change. Gold in these deposits is often found in quartz veins or as fine gold particles mixed with other minerals.
• These deposits are common in regions with active volcanic activity, where hot water from underground sources rises to the surface, often in association with geysers and hot springs.

Gold in seawater

Gold is present in trace amounts in seawater. It is estimated that there are around 13 billion metric tons of gold dissolved in the world’s oceans, but the concentration is extremely low, approximately 0.00000001 parts per million. While this makes gold in seawater technically accessible, the amount is not economically easy for extraction using current technologies.

One study found that there is only one gram of gold for every 100 million metric tons of ocean water in the Atlantic and North Pacific.

Global Distribution of Gold

Gold is distributed unevenly across the planet, with certain regions being more prolific in gold production due to favorable geological conditions. Around 31% of the world’s gold production by 2022 will come from three countries: Russia, China, and Australia. Some of the largest gold-producing countries include:

South Africa

• South Africa is home to the world’s largest gold deposit, the Witwatersrand Basin, which has produced billions of ounces of gold since its discovery in the late 19th century. The deposits in this region are primarily lode gold found in quartz veins within the ancient geological rock formations of the Kaapvaal Craton.

China

• China is the world’s largest producer of gold. Gold in China is found in both hard rock (lode) deposits and placer deposits. The Shandong and Henan provinces have large mining operations that contribute to the country’s gold production.

Australia

• Australia is another major producer of gold, with vast gold fields located in Western Australia, including the Kalgoorlie-Boulder region. Australia has both hard rock and placer gold deposits, and it continues to be one of the top gold exporters in the world.

Russia

• Russia is also a leading producer of gold, with extensive gold deposits in Siberia and the Far East regions. Hydrothermal deposits are common in Russia’s gold mining operations.

United States

• The United States is one of the top gold producers, particularly in Nevada, which contains some of the largest gold mines in the world. Gold in Nevada is primarily found in lode deposits, often in the form of low-grade ore that is processed using cyanide extraction.

Uses of Gold

Gold has been highly valued for centuries and has a wide range of uses due to its unique physical and chemical properties, including its conductivity, corrosion resistance, malleability, and aesthetic appeal. Below are the primary uses of gold:

1. Pure gold (24-karat) is too soft for most jewelry applications, so it is often alloyed with metals like copper, silver, and nickel to increase its strength while maintaining its color. Popular alloys include 18k, 14k, and 10k gold. Gold’s attractive color, malleability, and resistance to tarnish make it an ideal for crafting. It has been used for centuries in jewelry making like rings, necklaces, earrings, and watches, etc.
2. Historically, gold has been used to mint coins and serve as a standard for currency (gold standard). Even today, gold coins are minted by various governments, including the U.S. Gold Eagle and South African Krugerrand. Still gold is not used in coin minting but remains a popular choice for investment, coins, bullion due to its stability.
3. It is used in connectors, switches, circuit boards, and microchips, particularly for high-end electronic devices like smartphones, computers, and high-performance audio equipment.
4. Gold’s non-reactive nature ensures that it will not degrade over time, providing long-lasting, reliable electrical connections.
5. Gold is used in the aerospace industry for reflective coatings, particularly in satellites and spacecraft. It is used to coat visors and windows of astronauts’ helmets, as it can reflect infrared radiation and protect sensitive equipment from heat.
6. Gold is used in various medical devices, such as pacemakers, stents, and other implantable devices, due to its non-reactivity and biocompatibility. Gold compounds are sometimes used to treat certain medical conditions, such as rheumatoid arthritis (via gold injections), and to develop anti-cancer drugs.
7. Gold is used in scientific equipment for its stability, conductivity, and ease of handling. For instance, it is often used in precision instruments, mirrors, and detectors in scientific experiments.

Prices of Gold

Gold prices have been hovering around the 1900$-2000 per ounce near an all-time high. For mining companies, higher gold prices can mean more profit per ounce if costs remain unaffected. According to the World Gold Council, mined gold production is expected to increase in 2023 and could surpass the record set in 2018 (3,300 tones), led by the expansion of existing projects in North America. The chances of record mine output could be higher if gold prices continue to increase. In November 2024 the gold prices in Pakistan is:

Conclusion

Gold is a rare, precious metal that occurs in specific geological environments, often in native form as nuggets or flakes, or as part of ore deposits. It is primarily found in regions with rich geological histories marked by tectonic activity, volcanic processes, and the circulation of hydrothermal fluids. Gold deposits can be divided into primary lode deposits, where gold is embedded in rock formations, and placer deposits, where gold is concentrated in riverbeds or other alluvial deposits. Though it is found in trace amounts in seawater, this source is not viable for large-scale extraction. The global distribution of gold is uneven, with major production centers in South Africa, China, Australia, Russia, and the United States.