The chemical symbol of gold, Au, derives from its Latin name Aurum and means “glowing dawn”. Gold is a precious metal and one of the most difficult to inert. It is also one of the most valuable metals existing in nature.
Gold has many special properties. Because of its softness it is easy to shape and melt. A gram of gold can be beaten into a hundred-meter long thread. Gold conducts electricity and heat well. Gold does not corrode, discolor or rust when exposed to air or water. Concentrated acids and bases cannot affect gold either. That is why golden objects maintain their shine for a very long time, while other metals like iron, copper and silver become tarnished by oxides and sulphides over time.
Gold is a heavy metal: its density is 19.32 kg/dm3. Gold melts at the temperature of 1 063ºC and its boiling point is 2 940ºC.
Historically, the global physical gold demand has largely come from jewelry, accounting for 55% of the demand in 2017. Pure gold is designated as 24 carats. However, as pure gold is soft, it is usually hardened by alloying it with other metals like silver and copper. The typical gold grade in jewelry is 18 carats when the alloy contains 75% gold and 25% other metals like silver and copper.
Due to its many special properties, gold is also used in industry. The conductivity and good corrosion resistance of gold make it ideal for coating contact areas in electronics and in tele industry’s high technology products, such as semiconductors, circuit boards and microchips. It is even used in window glasses and in optics to moderate heat and light transmission. The dental industry is also a considerable user of gold. Gold is also increasingly used in the medical sector.