It’s been discovered on every continent on earth, it’s edible, our oceans contain nearly 20 million tonnes of it, and it’s perhaps the metal most infused with symbolism. Most people may associate gold with high-quality jewellery or wealth, but one of the world’s oldest precious metals also has a number of incredible properties and a multitude of uses. It could even play a significant role in helping Zambia to move away from its reliance on copper.
Read on to discover five things that you might not know about gold.
1. Zambia’s ‘mini gold rush’ represents exciting potential for gold mining
In August 2019, a group of primary school students in the Mwinilunga District of North-Western province were found playing with pieces of raw gold by their teacher. The students had no idea of the gold nuggets’ value and said they had gotten them from the nearby Kasensele River. Once word had spread about the discovery of gold in the Kasensele River (following heavy rains during the last wet season) people flooded to the area, hoping to get a share of the action.
The Kasensele River has now been secured, with President Lungu announcing that government will allow miners with licences to start mining the area’s gold under certain conditions. The geological survey department has been called on to conduct exploration on gold deposits in the province, since the surprise findings.
Mines Ministry Permanent Secretary Paul Chanda recently told the Zambian Business Times that government wants to encourage Zambians to invest in gold mining, seeing potential for local communities to participate in the sector via small-scale artisanal mining. The Ministry says it has already backed the formation of cooperatives in local communities to spur an interest in gold mining.
With copper remaining Zambia’s number one export (with raw copper accounting for approximately 47% of the country’s total exports, and refined copper accounting for 27%), reliance on the red metal is precarious. A burgeoning gold mining sector could provide Zambia with the diversification away from copper that it so badly needs. But government’s mineral tax hike in January 2019, which included a new 15% export duty for precious metals including gold, will make it less attractive to develop gold assets in Zambia. The current fiscal regime, unfortunately, is far more likely to stifle growth in this sector, rather than encourage it.
2. Gold is essential in spacecraft and satellites
In the near-vacuum of space, with no atmosphere to act as a barrier, radiation is the dominant form of heat transfer — and also one of the biggest threats to the delicate electronic components found in spacecraft and satellites. Gold is well-equipped for reflecting solar radiation back into space, enabling important instruments to continue operating under these extreme conditions.
Truth be told, copper, aluminium and silver reflect just as much infrared and UV radiation as gold, but the advantage of gold in space is the metal’s ability to absorb an enormous amount of visible light. This significantly reduces the chance of astronauts being blinded. The trick is to allow just enough light to pass through an astronaut’s gold-layered visor so that they can see, while deflecting infrared radiation. Without the thin layer of gold that you find on astronauts’ visors, their eyes would be burned by intense infrared light.
Most of the micro-electronics used in spacecraft and satellites are made of gold, too. This is because, while gold is an excellent electrical conductor, it also resists corrosion and static electricity build-up, allowing onboard electronics to perform reliably and with less maintenance.
3. Gold is the world’s most malleable metal
Without the thin layer of gold that you find on astronauts’ visors, their eyes would be burned by intense infrared light.
Malleability is a measure of how easily something can be hammered or pressed into various shapes (usually thin sheets), and gold is the most malleable metal on the planet. Just one gram of gold (the size of a grain of rice) can be hammered into a sheet that nearly covers a whole square metre.
Thin sheets of gold — usually known as gold leaf — are used for gilding ornaments, lettering, and creating edgings on ceramics, glass, paper and textiles. Depending on the type, one sheet of gold leaf can be 400 times thinner than a human hair. In fact, gold is so malleable that it can actually be beaten into a transparent sheet!
4. Gold can only compete with platinum for ductility
Ductile metals are, essentially, the opposite of brittle metals, and can be drawn out into thin wires — and still keep their toughness. Gold is listed by the Guinness World Records as “most ductile element”, based on an experiment in which one gram of gold was drawn into a wire 2.4 kilometres long. Not only was it long, it was ultra thin, measuring approximately five microns. To put that in perspective, the average human hair has a thickness of around 75 microns. Thin gold wires can even be used as thread.
But platinum’s ductility has since attracted attention in debates online, suggesting that it is, in fact, the more ductile metal. An article called The Platinum Decathlon points out that a platinum rod measuring 10 centimetres in length and 1 centimetre in diameter can be drawn into a single wire approximately 2,777 kilometres long, translating to a length of around 16.5 kilometres per gram. By this standard, platinum easily beats gold’s 2.4 kilometres per gram.
But the methods used to test each of the elements’ ductility were not the same, and platinum in particular relied on a few tricks to assist the lengthening process. After being drawn out to a thickness of 0.01 millimetres, the platinum was embedded into silver, which gave it additional structure during the remainder of the drawing-out process. Finally, the silver was dissolved off of the platinum, which left a very long, 0006 millimetre thick wire behind. It’s possible that similar methods may allow gold to achieve lengths comparable to platinum in ductility tests. But, for now, gold remains the official holder of the “most ductile element” title.
5. Gold is found (and lost) in millions of electronic devices
Perhaps the most important industrial use of gold is in the manufacturing of electronic devices. Gold’s excellent conductive properties and resistance to corrosion makes it the ideal choice for reliably transporting the tiny electrical currents that modern electronic devices use.
Gold is listed by the Guinness World Records as “most ductile element”, based on an experiment in which one gram of gold was drawn into a wire 2.4 kilometres long.
From smartphones, calculators and GPS units, to larger appliances like televisions, gold plays a part in production, usually within printed circuit boards. One standard laptop contains about 60 micrograms of gold, which might sound minuscule, but the sheer number of devices containing gold certainly makes it add up. Scotland’s University of Edinburgh estimates that 300 tonnes of gold are used in the production of electronic devices every single year.
Unfortunately, the growing appetite for new gadgets — along with a generally low rate of recycling — leads to a lot of wastage. The enormous cumulative amount of gold lost via discarded electronic devices each year translates into mind-boggling figures. Imagine: More gold is recoverable from a tonne of personal computers than from 17 tonnes of gold ore.
If you consider that around 7% of the world’s gold supply is currently contained within electronics, it’s not entirely implausible to imagine a day when “mining” previously-used metals for their repurposing becomes common practice.
But, until then, hopes remain high for Zambia to find a way for its people to fully benefit from these newly-discovered resources, right here at home.