Visualizing the Scale and Composition of the Earth's Crust
Connect with us

Mining

Visualizing the Scale and Composition of the Earth’s Crust

Published

on

Visualizing the Scale and Composition of the Earth’s Crust

For as long as humans have been wandering the top of Earth’s crust, we’ve been fascinated with what’s inside.

And Earth’s composition has been vital for our advancement. From finding the right kinds of rocks to make tools, all the way to making efficient batteries and circuit boards, we rely on minerals in Earth’s crust to fuel innovation and technology.

This animation by Dr. James O’Donoghue, a planetary researcher at the Japan Aerospace Exploration Agency (JAXA) and NASA, is a visual comparison of Earth’s outer layers and their major constituents by mass.

What is the Composition of Earth’s Crust?

The combined mass of Earth’s surface water and crust, the stiff outermost layer of our planet, is less than half a percent of the total mass of the Earth.

There are over 90 elements found in Earth’s crust. But only a small handful make up the majority of rocks, minerals, soil, and water we interact with daily.

1. Silicon

Most abundant in the crust is silicon dioxide (SiO2), found in pure form as the mineral quartz. We use quartz in the manufacturing of glass, electronics, and abrasives.

Why is silicon dioxide so abundant? It can easily combine with other elements to form “silicates,” a group of minerals that make up over 90% of Earth’s crust.

Clay is one of the better-known silicates and micas are silicate minerals used in paints and cosmetics to make them sparkle and shimmer.

MineralMajor ElementsPercentage of Crust
Plagioclase FeldsparO, Si, Al, Ca, Na39%
Alkali FeldsparO, Si, Al, Na, K12%
QuartzO, Si12%
PyroxeneO, Si, Mg, Fe11%
AmphiboleO, Si, Mg, Fe5%
Non-silicatesVariable8%
MicasO, Si, Al, Mg, Fe, Ca, Na, K5%
Clay MineralsO, Si, Al, Mg, Fe, Ca, Na, K5%
Other SilicatesO, Si3%

2. Aluminum and Calcium

SiO2 bonds very easily with aluminum and calcium, our next most abundant constituents. Together with some sodium and potassium, they form feldspar, a mineral that makes up 41% of rocks on Earth’s surface.

While you may not have heard of feldspar, you use it every day; it’s an important ingredient in ceramics and it lowers the melting point of glass, making it cheaper and easier to produce screens, windows, and drinking glasses.

3. Iron and Magnesium

Iron and magnesium each make up just under 5% of the crust’s mass, but they combine with SiO2 and other elements to form pyroxenes and amphiboles. These two important mineral groups constitute around 16% of crustal rocks.

Maybe the best known of these minerals are the two varieties of jade, jadeite (pyroxene) and nephrite (amphibole). Jade minerals have been prized for their beauty for centuries, and are commonly used in counter-tops, construction, and landscaping.

Some asbestos minerals, now largely banned for their cancer-causing properties, belong to the amphibole mineral group. They were once in high demand for their insulating and fire-retardant properties and were even used in brake pads, cigarette filters, and as artificial snow.

4. Water

Surprisingly, even though it covers almost three quarters of Earth’s surface, water (H2O) makes up less than 5% of the crust’s mass. This is partly because water is significantly less dense than other crustal constituents, meaning it has less mass per volume.

Breaking Earth’s Crust Down by Element

Though there are many different components that form the Earth’s crust, all of the above notably include oxygen.

When breaking down the crust by element, oxygen is indeed the most abundant element at just under half the mass of Earth’s crust. It is followed by silicon, aluminum, iron, calcium, and sodium.

All other remaining elements make up just over 5% of the crust’s mass. But that small section includes all the metals and rare earth elements that we use in construction and technology, which is why discovering and economically extracting them is so crucial.

What Lies Below?

As the crust is only the outermost layer of Earth, there are other layers left to contemplate and discover. While we have never directly interacted with the Earth’s mantle or core, we do know quite a bit about their structure and composition thanks to seismic tomography.

The Upper Mantle

At a few specific spots on Earth, volcanic eruptions and earthquakes have been strong enough to expose pieces of the upper mantle, which are also made of mostly silicates.

The mineral olivine makes up about 55% of the upper mantle composition and causes its greenish color. Pyroxene comes in second at 35%, and calcium-rich feldspar and other calcium and aluminum silicates make up between 5–10%.

Going Even Deeper

Beyond the upper mantle, Earth’s composition is not as well known.

Deep-mantle minerals have only been found on Earth’s surface as components of extra-terrestrial meteorites and as part of diamonds brought up from the deep mantle.

One thing the lower mantle is thought to contain is the silicate mineral bridgmanite, at an abundance of up to 75%. Earth’s core, meanwhile, is believed to be made up of iron and nickel with small amounts of oxygen, silicon, and sulphur.

As technology improves, we will be able to discover more about the mineral and elemental makeup of the Earth and have an even better understanding of the place we all call home.

green check mark icon

This article was published as a part of Visual Capitalist's Creator Program, which features data-driven visuals from some of our favorite Creators around the world.

Subscribe to Visual Capitalist
Click for Comments

Mining

The 50 Minerals Critical to U.S. Security

This graphic lists all minerals that are deemed critical to both the economic and national security of the United States.

Published

on

The 50 Minerals Critical to U.S. Security

This was originally posted on Elements. Sign up to the free mailing list to get beautiful visualizations on natural resource megatrends in your email every week.

The U.S. aims to cut its greenhouse gas emissions in half by 2030 as part of its commitment to tackling climate change, but might be lacking the critical minerals needed to achieve its goals.

The American green economy will rely on renewable sources of energy like wind and solar, along with the electrification of transportation. However, local production of the raw materials necessary to produce these technologies, including solar panels, wind turbines, and electric vehicles, is lacking. Understandably, this has raised concerns in Washington.

In this graphic, based on data from the U.S. Geological Survey, we list all of the minerals that the government has deemed critical to both the economic and national security of the United States.

What are Critical Minerals?

A critical mineral is defined as a non-fuel material considered vital for the economic well-being of the world’s major and emerging economies, whose supply may be at risk. This can be due to geological scarcity, geopolitical issues, trade policy, or other factors.

In 2018, the U.S. Department of the Interior released a list of 35 critical minerals. The new list, released in February 2022, contains 15 more commodities.

Much of the increase in the new list is the result of splitting the rare earth elements and platinum group elements into individual entries rather than including them as “mineral groups.” In addition, the 2022 list of critical minerals adds nickel and zinc to the list while removing helium, potash, rhenium, and strontium.

Mineral Example UsesNet Import Reliance
BerylliumAlloying agent in aerospace, defense industries 11%
AluminumPower lines, construction, electronics 13%
ZirconiumHigh-temparature ceramics production 25%
PalladiumCatalytic converters40%
GermaniumFiber optics, night vision applications50%
LithiumRechargeable batteries 50%
MagnesiumAlloys, electronics 50%
NickelStainless steel, rechargeable batteries 50%
TungstenWear-resistant metals50%
BariteHydrocarbon production75%
ChromiumStainless steel75%
TinCoatings, alloys for steel 75%
CobaltRechargeable batteries, superalloys76%
PlatinumCatalytic converters 79%
AntimonyLead-acid batteries, flame retardants 81%
ZincMetallurgy to produce galvanized steel 83%
TitaniumWhite pigment, metal alloys88%
BismuthMedical, atomic research 94%
TelluriumSolar cells, thermoelectric devices95%
VanadiumAlloying agent for iron and steel96%
ArsenicSemi-conductors, lumber preservatives, pesticides 100%
CeriumCatalytic converters, ceramics, glass, metallurgy100%
CesiumResearch, development100%
DysprosiumData storage devices, lasers100%
ErbiumFiber optics, optical amplifiers, lasers100%
EuropiumPhosphors, nuclear control rods 100%
FluorsparManufacture of aluminum, cement, steel, gasoline100%
GadoliniumMedical imaging, steelmaking100%
GalliumIntegrated circuits, LEDs100%
GraphiteLubricants, batteries100%
HolmiumPermanent magnets, nuclear control rods100%
IndiumLiquid crystal display screens 100%
LanthanumCatalysts, ceramics, glass, polishing compounds100%
LutetiumScintillators for medical imaging, cancer therapies 100%
ManganeseSteelmaking, batteries 100%
NeodymiumRubber catalysts, medical, industrial lasers 100%
NiobiumSteel, superalloys100%
PraseodymiumPermanent magnets, batteries, aerospace alloys100%
RubidiumResearch, development in electronics 100%
SamariumCancer treatment, absorber in nuclear reactors 100%
ScandiumAlloys, ceramics, fuel cells100%
TantalumElectronic components, superalloys100%
TerbiumPermanent magnets, fiber optics, lasers100%
ThuliumMetal alloys, lasers 100%
YtterbiumCatalysts, scintillometers, lasers, metallurgy 100%
YttriumCeramic, catalysts, lasers, metallurgy, phosphors 100%
IridiumCoating of anodes for electrochemical processesNo data available
RhodiumCatalytic converters, electrical componentsNo data available
RutheniumElectrical contacts, chip resistors in computersNo data available
HafniumNuclear control rods, alloysNet exporter

The challenge for the U.S. is that the local production of these raw materials is extremely limited.

For instance, in 2021 there was only one operating nickel mine in the country, the Eagle mine in Michigan. The facility ships its concentrates abroad for refining and is scheduled to close in 2025. Likewise, the country only hosted one lithium mine, the Silver Peak Mine in Nevada.

At the same time, most of the country’s supply of critical minerals depends on countries that have historically competed with America.

China’s Dominance in Minerals

Perhaps unsurprisingly, China is the single largest supply source of mineral commodities for the United States.

Cesium, a critical metal used in a wide range of manufacturing, is one example. There are only three pegmatite mines in the world that can produce cesium, and all were controlled by Chinese companies in 2021.

Furthermore, China refines nearly 90% of the world’s rare earths. Despite the name, these elements are abundant on the Earth’s crust and make up the majority of listed critical minerals. They are essential for a variety of products like EVs, advanced ceramics, computers, smartphones, wind turbines, monitors, and fiber optics.

After China, the next largest source of mineral commodities to the United States has been Canada, which provided the United States with 16 different elements in 2021.

The Rising Demand for Critical Minerals

As the world’s clean energy transitions gather pace, demand for critical minerals is expected to grow quickly.

According to the International Energy Association, the rise of low-carbon power generation is projected to triple mineral demand from this sector by 2040.

The shift to a sustainable economy is important, and consequently, securing the critical minerals necessary for it is just as vital.

Continue Reading

Energy

Visualizing China’s Dominance in Clean Energy Metals

Despite being the world’s biggest carbon emitter, China is also a key producer of most of the critical minerals for the green revolution.

Published

on

Visualizing China’s Dominance in Clean Energy Metals

This was originally posted on Elements. Sign up to the free mailing list to get beautiful visualizations on natural resource megatrends in your email every week.

Renewable sources of energy are expected to replace fossil fuels over the coming decades, and this large-scale transition will have a downstream effect on the demand of raw materials. More green energy means more wind turbines, solar panels, and batteries needed, and more clean energy metals necessary to build these technologies.

This visualization, based on data from the International Energy Agency (IEA), illustrates where the extraction and processing of key metals for the green revolution take place.

It shows that despite being the world’s biggest carbon polluter, China is also the largest producer of most of the world’s critical minerals for the green revolution.

Where Clean Energy Metals are Produced

China produces 60% of all rare earth elements used as components in high technology devices, including smartphones and computers.

The country also has a 13% share of the lithium production market, which is still dominated by Australia (52%) and Chile (22%). The highly reactive element is key to producing rechargeable batteries for mobile phones, laptops, and electric vehicles.

China's ShareExtractionProcessing
Copper 8%40%
Nickel 5%35%
Cobalt 1.5%65%
Rare Earths 60%87%
Lithium13%58%

But even more than extraction, China is the dominant economy when it comes to processing operations. The country’s share of refining is around 35% for nickel, 58% for lithium, 65% for cobalt, and 87% for rare earth elements.

Despite being the largest economy in the world, the U.S. does not appear among the largest producers of any of the metals listed. To shorten the gap, the Biden administration recently launched an executive order to review the American strategy for critical and strategic materials.

It’s also worth noting that Russia also does not appear among the top producers when it comes to clean energy metals, despite being one of the world’s leading producers of minerals like copper, iron, and palladium.

Low Regulation in the Clean Metal Supply Chain

While China leads all countries in terms of cobalt processing, the metal itself is primarily extracted in the Democratic Republic of Congo (DRC). Still, Chinese interests own 15 of the 17 industrial cobalt operations in the DRC, according to a data analysis by The New York Times and Benchmark Mineral Intelligence.

Unfortunately, the DRC’s cobalt production has been criticized due to reports of corruption and lack of regulation.

Part of the Congolese cobalt comes from artisanal mines with low regulation. Of the 255,000 Congolese artisanal miners, an estimated 40,000 are children, some as young as six years old.

The Rise of Clean Energy Metals

The necessary shift from fossil fuels to renewable energy opens up interesting questions about how geopolitics, and these supply chains, will be affected.

In the race to secure raw materials needed for the green revolution, new world powers could emerge as demand for clean energy metals grows.

For now, China has the lead.

Continue Reading

Subscribe

Popular