Think of Earth’s crust as the planet’s outermost skin: a thin layer packed with common elements to form the foundation of silicate minerals and rocks. The chemical composition here is different from what’s deeper inside, like the Earth’s mantle or core.
These are just a few elements Earth’s crust comprises, ranked by the percent of the weight they occupy.
1. Oxygen (46%)
Oxygen reigns supreme in the Earth’s crust, accounting for nearly half its total mass. It also obviously plays a major part in the human body’s chemical composition.
While you might think of oxygen as the gas you breathe, here it’s busy forming oxides and partnering with other common elements like silicon. Oxygen is crucial in silicate minerals like quartz (silicon dioxide) and feldspar.
2. Silicon (27%)
The second-most abundant element in the crust is silicon, famous for making silicon chips and quartz crystals.
Silicon loves to form compounds, especially silicon dioxide, found in everything from metamorphic rocks to beach sand. Its ability to link up with oxygen creates structures vital to life on Earth.
3. Aluminum (8%)
Say hello to aluminum, the third-most abundant element in the crust. Despite being lightweight, aluminum packs a punch as a common element in crustal abundance, appearing in minerals like bauxite and feldspar.
It’s a big player in the construction of common oxides and essential to industries worldwide.
4. Iron (5%)
Iron isn’t just a major component of Earth’s core; it also hangs out in the crust, forming oxides like hematite and magnetite. These compounds give soil its reddish hue and make up a significant portion of metamorphic rocks.
Fun fact: Iron accounts for much of the weight of Earth’s magnetic field!
5. Calcium (4%)
The No. 5 spot goes to calcium, which forms common minerals like calcite and gypsum. As a vital part of limestone, it plays a starring role in Earth’s natural beauty, from towering cliffs to coral reefs. Plus, calcium is an essential nutrient for both plants and humans.
