Gold Curiosities

One troy ounce (31.1 g) of gold can be hammered into a translucent sheet covering over 9 square metres — thin enough to let light through. Gold leaf used in art and architecture can be as thin as 0.1 microns, about 1,000 times thinner than a human hair.

Heavy elements like gold cannot be created inside ordinary stars. They are only formed during neutron star mergers — catastrophic collisions so energetic they briefly outshine entire galaxies. The gold in your jewellery was scattered across space billions of years ago by one such event.

Scientists estimate that Earth’s iron-nickel core contains roughly 1.6 quadrillion tonnes of gold — enough to cover the entire planet’s surface in a layer 4 metres deep. It sank to the core when Earth formed. All minable gold near the surface arrived via asteroid impacts billions of years ago.

24-karat gold is totally non-toxic and passes through the human body without being absorbed or reacting with anything. This is why gold leaf appears on luxury food and cocktails worldwide. It has no taste, no smell, and zero nutritional value — but no harm either.

Earth’s oceans contain an estimated 20 million tonnes of dissolved gold — roughly 100 times all the gold ever mined. It is so dilute (around 13 parts per trillion) that no economically viable extraction method exists. If it could be extracted, it would be worth roughly $1 quadrillion.

Ancient Egypt was producing gold bars stamped with weight and purity as early as 4,000 BCE. The first true gold coins were struck in Lydia (modern Turkey) around 600 BCE. No other substance has served continuously as a global store of value for as long as gold has.

Every modern smartphone contains about 0.03 grams of gold, used in circuit board connectors because gold doesn’t tarnish or corrode. One tonne of discarded smartphones yields more gold than one tonne of gold ore from most mines — making urban mining a growing industry.

NASA uses thin gold coatings on spacecraft visors and instruments because gold is an outstanding reflector of infrared radiation. The James Webb Space Telescope’s primary mirror is coated in gold to maximise its ability to detect heat from the earliest galaxies in the universe.

Olympic “gold” medals haven’t been solid gold since 1912. Today’s gold medals are made from at least 92.5% silver, plated with just 6 grams of gold. A solid gold Olympic medal at today’s prices would be worth over $500,000 — making it entirely impractical to award at the games.