Material World: A Substantial Story of Our Past and Future

by Ed Conway

For a standard gold bar (400 troy ounces) they would have to dig about 5,000 tonnes of earth. That’s nearly the same weight as ten fully laden Airbus A380 super-jumbos, the world’s largest passenger planes – for one bar of gold.

But think, for a moment, about what gold actually does. It plays an important if somewhat fringe role in electronics and chemistry, but that accounts for less than a tenth of demand these days. Instead, its primary uses are in jewellery, decoration and as an asset for those who worry about economic disaster.

Sacrilegious as this will sound to jewellers and jumpy investors, the world would probably not cease to function, nor civilisation grind to a halt, if we suddenly ran out of gold.1

Irishman called Pat Clayton, was crossing the lip of one such dune in December 1932 when he suddenly heard a crunching sound beneath his wheels. He got out to investigate and discovered that the desert was covered in great sheets of yellow glass. Only in the late 1990s did scientists finally confirm that the canary-yellow beetle at the heart of Tutankhamen’s necklace was carved from the very same material Pat Clayton had crunched over 500 miles away in the Great Sand Sea. The Egyptian boy king was buried in the Valley of the Gods with a precious stone plucked from the Land of the Dead. This luminous stone was not forged like diamonds, sapphires and other such gems over thousands of years of heat and pressure within the earth’s crust. Instead, it was created in the blink of an eye by a falling star. That meteor 29 million years ago had turned the sand into a kind of glass – Libyan desert glass.

that silica content can vary significantly. The glasses we drink from or have in our window panes typically have about 70 per cent silica. The silica content of obsidian and of most tektites is generally between 65 per cent and 80 per cent. The silica content of Libyan desert glass, on the other hand, is a staggering 98 per cent. Not only did this make it the purest naturally occurring glass to have been discovered anywhere, it was purer than anything humankind could create – for the time being at least.

During the Napoleonic Wars Britain attempted to starve France of glass. In the early days of the United States, English glassmakers were forbidden from emigrating there, by a government determined to protect the domestic industry via regulation and taxes.

The paradox is that, despite it being one of the very oldest human-made substances, scientists still struggle to comprehend why glass behaves the way it does. Glass seems to defy most molecular laws. As one glassmaker put it, glass is not a material; it’s a state.

The world’s most famous silver sands – at least to those who know about these things – are probably those at Fontainebleau, a forest just south of Paris. The famous glass pyramid at the Louvre is made of Fontainebleau sand. There are silver sands in Mol in Belgium, in Maastricht in the Netherlands and Lippe in Germany, as well as in Canada, the US, Brazil and other corners of the world. But while they are not exactly scarce, nor are they commonplace. Some countries have no such sands; that, indeed, was the assumption in Britain for a long time, until the discovery of Lochaline about a century ago.

Composed of 99 per cent silica with barely a smidge of iron oxide, this sand is unlike any you have come across before. If you are looking to build a sandcastle, you’ve come to the wrong place. Lochaline sand is so fine and floury it simply falls through your fingers a little like caster sugar.

‘my sand’, as she called it, and the other with a more typical glass sand, with a few more parts per million of iron. One bottle had a green hue in its thickest parts; the other, the Lochaline sand bottle, was nearly completely clear.

Allied troops were routinely terrorised by German marksmen who could seemingly defy the laws of physics by killing from so far away. The brand name etched on the side of nearly all these riflescopes was Zeiss and the glass inside them came from a separate, if related, firm: Schott. Otto Schott was a German chemist who spent much of his life experimenting with ways to improve glass, adding elements from the periodic table to a molten mix, one by one, to see what kinds of effects they would elicit.

By 1914, Britain was reliant on Germany, or rather Zeiss, for some 60 per cent of all its precision glass (France provided the next 30 per cent with only 10 per cent coming from domestic firms,

In September 1914 one of the British Army’s leading lights, Field Marshal Lord Roberts, issued an ‘almost despairing appeal’ for the general public to donate any binoculars, opera glasses and telescopes lying around in their homes to troops heading to the trenches.

Why was Germany prepared to provide Britain with technology that could be used to kill Germans? The main answer, it turns out, was that they desperately needed something in return: rubber. Not only were Britain and its allies – or rather its colonies – among the world’s biggest rubber producers, they had successfully blockaded German imports, starving the country of natural resources of rubber latex, an essential ingredient in tyres, tubing and fan belts in engines.

You have probably heard of the window tax, first levied in 1696, during the reign of William III. This was long before the introduction of income taxes, and in a bid to raise money the government reasoned that the better off someone was, the bigger their house and the more windows it would have, so they taxed people based on the number of windows in their property. The upshot was that many homeowners bricked up their windows in an effort to reduce their tax bill; you can still see many such ‘blind’ windows around England today.

Maybe he chose a site with desert sands, whose rounded edges do not cohere. Even more likely, he built it atop alluvial sands, which are flat and hard in the dry season but can suddenly become loose and unstable when the rains come and rivers burst their banks.

Consider: Singapore says it imported around 600 million tonnes of sand from elsewhere between 2000 and 2020. Yet the countries exporting their sand to Singapore say they only sent 280 million tonnes. There is, in short, a missing 320 million tonnes for which no one can account. Someone must have mined it, but no one is owning up to it.2

Long stretches of coastline in Morocco and Western Sahara have been removed to provide sand, which is shipped to Europe and the Canary Islands, where it is used for construction and to replenish tourist beaches (you might be surprised at how many of Europe’s beaches are in fact created from imported sand).

concrete, a mixture of sand, aggregate and cement, is nonetheless quite extraordinary.

if you were looking to improve the lot of low-income families in poor parts of the developing world, which of the following would you provide for them? A bundle of cash, nutritional supplements or a bag of cement?

Replacing dirt tracks with paved roads (i.e. concrete) has been shown to increase the wages of those who work near them by more than a quarter and also increases the proportion of children who enrol in school.15

A couple of centuries ago, nearly all building was done with brick or timber; today concrete accounts for about 80 per cent of all the materials we use in construction.

cement is the magic ingredient, the glue, that sticks concrete together. The cement itself is a powder formed when you roast and crush limestone or chalk along with clay, sand and, occasionally, some other additives such as iron oxide.

To put it another way, the reason cement has changed the world is not merely because it has magical qualities but because it is cheap and it is everywhere.

The Pantheon may have lasted more than 2,000 years, but the quality of some newly constructed concrete housing in China is so poor that it has an average lifespan of about 20 years.

For all the attention lavished on other sources of greenhouse gases such as aviation or deforestation, the production of cement generates more CO2 than those two sectors combined. Cement production accounts for a staggering 7–8 per cent of all carbon emissions.

But the chemical reaction is a far harder nut to crack. Humans have been heating calcium carbonate to produce calcium oxide or quicklime, the central reaction in the production of cements, for thousands of years; indeed, this process was humankind’s very first large-scale carbon emission, millennia before the era of fossil fuels. And we have yet to find an easy way of removing the carbon without producing carbon dioxide.

more than 50 per cent of the new patents in novel concretes have been taken out by Chinese companies and academic institutions.24

This final distinction is all-important, for the vast majority of these raw ingredients for the technological revolution are mined and refined in China these days. Ferroglobe, which also has quartz mines in the US, Canada and South Africa, is one of the rare exceptions.

For every 6 tonnes of raw materials thrown into the melt – quartz, coal and woodchips – about a tonne of silicon metal comes out. The mechanics of this furnace, by the way, are what explains why granular sand won’t work as the raw material for silicon chips. While there’s nothing wrong with its chemical composition, sand grains are simply the wrong size.

What is striking, however, is that China has yet to master the manufacture of the pièce de résistance of the silicon world: semiconductor grade polysilicon. This can have as many as ten nines (99.99999999 per cent purity),

‘Here’s something scary,’ says one veteran of the sector. ‘If you flew over the two mines in Spruce Pine with a crop duster loaded with a very particular powder, you could end the world’s production of semiconductors and solar panels within six months.’ No high-purity quartz means no Czochralski crucibles, which means no monocrystalline silicon wafers, which means, well, the end of computer chip manufacture as we know it. We would adapt; find a new process or an alternative substance. But it would be a grisly few years.

One theory is that part of the reason Taiwan has succeeded where China has failed is that it simply struck it lucky with its timing; back in the 1960s and 1970s when it sent many of its graduates to university in the US, they ended up studying engineering and working at companies like Intel and Texas Instruments. They brought that technical knowledge back to Taiwan. But by the time China opened up and began sending students to the US in the 1990s and 2000s, the American tech industry had changed. The companies in ascendancy were software firms like Microsoft, Amazon and Google. That generation of Chinese students came home and, rather than establishing a hardware industry, they used what they had learned in the US to set up internet services firms.

China spends more money on importing computer chips these days than it does importing oil. Indeed, according to Chris Miller, the author of a history of silicon chips, China’s semiconductor import costs as of 2017 were greater than Saudi Arabia’s total revenue from oil exports, or for that matter the entire global trade in aircraft. ‘No product,’ he says, ‘is more central to international trade than semiconductors.’

Historians have long theorised that the reason much of human civilisation began on coastlines was because of easy access to salt.

The Romans were among the first culture to provide formal salt rations to their soldiers – each one received an allowance, which is where the word ‘salary’ comes from, though it might better be thought of as a form of health insurance than cash, since they were also paid in money.

Khewra salt before; it is better known these days as pink Himalayan salt, though the mine is actually about 200 miles from the Himalayan foothills, making this a cheeky bit of marketing, a little like bottling London’s River Thames and selling it as Yorkshire Dales spring water.

Celtic and then Roman settlements were built around these springs in Middlewich and Northwich, Nantwich and Leftwich. Over time the -wich suffix in a town’s name came to denote saltworking.

‘What keeps roads safe is not salt,’ said Chris, ‘it’s brine. So you need the salt to dissolve and then you get an immediate de-icing effect. If you’re in a heavy-traffic road [the grains] will break up quicker and you have to go out and reapply them.’

When large deposits were discovered in the muds of India’s River Ganges it precipitated the country’s occupation. Within a few decades saltpetre became one of the most important items traded by the British East India Company.

Chilean nitrates helped feed and arm the world. It was Chilean nitrates in the Allied explosives that rained down on the trenches in the First World War. Their revenues helped finance the construction of more roads and railroads, electrical networks and plumbing, and helped Chile build an advanced military and attain the twentieth-century trappings enjoyed by many European countries. Thanks to this white salt, Chile became the richest nation in Latin America.

So when the First World War began, no other country was more exposed. Indeed, it’s telling that the war’s very first naval engagement between German and British ships occurred not in the seas of Europe but off the Pacific coast of Chile, as the nations attempted to wrest control of the shipping lanes for nitrates.

Eurasia continues to collide with Africa, geologists expect that in the coming millions of years the strait will close again, this time permanently. The Mediterranean will eventually dry up and disappear altogether, leaving a layer of buried salts in its wake, much like the Zechstein Sea.

Much of Morocco’s phosphate rock is to be found in the disputed territory of Western Sahara, where it provides one of the area’s most important exports, alongside sand used to replenish the beaches of the Canary Islands.

polyhalite is simply dug out of the ground, crushed and then sold rather than artificially processed like most fertilisers, it could be certified as organic.

When you mine gold more than 99.99 per cent of the rock will go to waste; with polyhalite every tonne of rock becomes a tonne of product. The only other mineral that compares is, well, salt.

There is a phrase you sometimes hear: if it’s not grown, it’s mined. Salt, however, is a substance we mine to help us grow – to provide the fertilisers for our crops and the building blocks for our drugs.

Not everything in the world is made of steel, but nearly everything in the world is made with machines made of steel.

we dig, blast and pump out of the planet’s surface each year. Sand and gravel: 43 billion tonnes; oil and gas: 8.1 billion tonnes; coal: 7.7 billion tonnes; iron ore: 3.1 billion tonnes. And

one end of the spectrum is cast iron or pig iron (so named because when it was first made it would set in a series of channels and moulds resembling a litter of piglets being nursed by their mother). This is a brittle metal with about 3–4 per cent carbon. At the other end is wrought iron, soft enough to be beaten with a hammer and very pure, with infinitesimally small quantities of carbon. In the middle is steel, which typically has less than 2 per cent carbon (and usually, in the case of most mild steels, such as those which once came from the mills at Azovstal, a fair bit less; well below 1 per cent).