Gold

Characteristics and Properties of Gold

• Gold is a bright, slightly orange-yellow, dense, soft, malleable, and ductile metal.
• It is a transition metal and one of the noble metals.
• Gold is one of the least reactive chemical elements and is solid under standard conditions.
• It often occurs in free elemental form, as nuggets or grains, in rocks, veins, and alluvial deposits.
• Gold can also occur naturally alloyed with other metals like copper and palladium.
• Gold is metallic yellow in appearance.
• Its standard atomic weight is 196.966570±0.000004.
• The boiling point of gold is 3243K (2970°C, 5378°F).
• The density of gold is 19.3g/cm³ (near room temperature).
• Gold has a thermal conductivity of 318W/(m⋅K).
• Gold is resistant to most acids, but it dissolves in aqua regia, forming a soluble tetrachloroaurate anion.
• It is insoluble in nitric acid alone, which is used to distinguish gold from other metals.
• Gold dissolves in alkaline solutions of cyanide, commonly used in mining and electroplating.
• It can also dissolve in mercury, forming amalgam alloys.
• Gold is diamagnetic, exhibiting no magnetic ordering.

Uses of Gold

• Gold has been used for coinage, jewelry, and art throughout history.
• It was previously used as a monetary standard.
• Gold is used in corrosion-resistant electrical connectors in electronic devices.
• It is used in infrared shielding, colored glass production, gold leafing, and tooth restoration.
• Certain gold salts are used as anti-inflammatories in medicine.

Isotopes of Gold

• Gold has one stable isotope, 197Au, which is its only naturally occurring isotope.
• There are 36 synthesized radioisotopes of gold, ranging in atomic mass from 169 to 205.
• The most stable radioisotope is 195Au with a half-life of 186.1 days.
• Gold isotopes decay through various processes such as proton emission, α decay, β decay, and electron capture.
• Gold also has several nuclear isomers, with the most stable being 198m2Au with a half-life of 2.27 days.

Origin and Occurrence of Gold

• Gold is thought to be produced in supernova nucleosynthesis and from the collision of neutron stars.
• It may have been present in the dust from which the Solar System formed.
• Most of the gold in the Earth's crust and mantle may have been delivered by asteroid impacts.
• Gold is found in ores in rock formed from the Precambrian time onward.
• It often occurs as a native metal in a gold/silver alloy.
• Native gold can be found in small particles embedded in rock, often with quartz or sulfide minerals.
• Lode deposits and placer deposits are common sources of gold.
• Gold can also occur in rare alloys with copper, lead, and mercury.
• Gold is present in the world's oceans, but in very low concentrations.

History, Trade, and Cultural Significance of Gold

• The oldest recorded use of metal by humans is gold, dating back to the late Paleolithic period.
• Gold artifacts appeared in Ancient Egypt and Mesopotamia during the 4th millennium BC.
• Gold was used for coinage in Lydia around 610 BC.
• European exploration of the Americas was fueled by reports of gold ornaments.
• The gold trade in West Africa was dominated by the Ashanti Empire.
• Alchemists attempted to produce gold from other substances.
• Gold is used in various cultural and religious contexts, such as in the Dome of the Rock and Sikh Golden Temple.
• Gold is often used as a standard of excellence and is awarded in various forms.
• Gold is associated with divine principles, such as the golden ratio and the golden rule.
• The fiftieth wedding anniversary is referred to as the golden anniversary.
• Gold holds significance in various religious traditions and rituals.

Gold Mentions

Gold Data Sources