Properties of gold

One of the reasons for gold’s high value is the properties that are unique to it, and desirable for a range of uses. It’s colour, lustre and rarity all make gold attractive to people, but the physical and chemical properties help elevate it to something more than just a shiny metal for jewellery and coins.

What are the properties of gold?

Many of the physical properties of gold are well known by us all; the bright, shiny yellow colour, and its incredible density have both captured the attention of people for thousands of years. These have been key in gold's adoption for art, jewellery and coins.

Gold is one of the ‘noble’ metals and is virtually chemically inert; it reacts with almost nothing. As such, 80% of gold found within ores is in its elemental state. This is also why gold does not tarnish over time, but it can make it difficult to refine. Most acids have little effect on gold, but Aqua Regia – a highly concentrated mix of nitric acid and hydrochloric acid – can dissolve it. Toxic chemicals like Mercury and Cyanide can also be used to form amalgams with gold, but environmental concerns mean these are prohibited or strictly regulated. It also has a very high melting point, further helping it stand up to many extreme situations.

Gold only has one stable isotope – ¹⁹⁷ Au – with other radioisotopes and nuclear isomers decaying over time. Thanks to the progress of nuclear physics, the ancient goal of alchemy (the transmutation of other chemical elements into gold) is now possible. Japanese physicist Hantaro Nagaoka successfully synthesised gold from mercury in 1924, finally solving the centuries old conundrum.

Today, mercury and platinum can be turned into gold through irradiation. This process however is unviable for large scale production, and synthesis of alternatives to gold unlikely, meaning that gold will continue to be rare for years to come.

Gold’s unique chemical properties mean that it is also incredibly useful. Learn more about the uses of gold.

Chemical properties of gold

Chemically speaking, gold is a very unique element. With a high electrical conductivity, high melting point, low reactivity, and high ductility, gold is ideal for electronics and as such is used extensively in industries worldwide. An ounce of gold can be stretched into a wire 2000 km long with a thickness of 1 µm (micrometer)!

Although silver is technically a better conductor, all of gold's properties combined make it the metal of choice for electronics. The fact it won't tarnish makes it an excellent long-term choice, ensuring it will remain conductive for much longer.

Gold's properties truly are special, a combination of many desirable qualities that make it a useful metal. It is this usefulness that ensures it will always have an intrinsic value, and cannot be devalued to 0.

Below are just some of the amazing (but highly technical) properties of gold that make it so special and irreplaceable in our society.