Gold is a chemical element with the symbol Au and atomic number 79, making it one of the higher atomic numbers in nature. It is orange-yellow, very dense, soft, malleable, and ductile, and a transition metal, belonging to group 11. It is used in jewelry and coins. In addition, it is valuable in the investment and manufacturing industries. Despite its high price, the precious metal is one of the most desirable commodities.
It is widely distributed throughout the earth’s crust and has a background concentration of 0.03 g/1000 kg (or ppm) by weight. Because it is highly dense, gold concentrates in streambeds and is found in small flakes or nuggets. It can be recovered through panning, a process known as electrolysis. The metal is often associated with pyrite and quartz, so it is also possible to recover it using a laboratory sluice.
The concentration of gold in oceans varies. It is found as very small particles embedded in rocks, often with quartz and sulfide minerals. Free gold is also present in the form of larger nuggets or flakes. This material ends up in alluvial deposits called placers, where it is concentrated. Its higher concentration is due to the presence of wind-blown dust or rivers. Approximately 15,000 tonnes of gold are expected to be found in the oceans every year.
Gold is considered the most malleable of all metals. A single atom-thick wire of gold can stretch for several millimeters without breaking. Nanowires, which are thin pieces of metal, distort by reorienting dislocations or migration of crystal twins, and subsequently deform and harden. In 1830, the world’s gold output was only 12 tonnes per year. Around 1830, new discoveries of gold in Alaska, California, and the Transvaal of South Africa brought new discoveries of gold to the attention of the world.
Gold is found in large quantities in the earth’s crust. The amount of gold in the oceans is about ten grams per cubic meter of water. It is widely distributed and reaches depths of a few hundred meters. It is commonly found in streambeds. It is a relatively dense metal and can be recovered by panning. It is a highly valuable metal and is used in jewelry. A small ounce of gold can be worth more than a gram.
China is the largest producer of gold. In 1848, a small mining operation in Yukon, Canada, was the first gold field to discover gold in the world. In the following years, the North American gold fields became the world’s largest supplier of the precious metal. The African Transvaal and Alaska now rival the Western United States in terms of the quantity of mined and unmined reserves. These discoveries made gold more popular in jewelry and in other forms.