Bulk Composition of Planet Earth by Mass

About This Dataset

This chart shows the bulk elemental composition of the entire planet Earth by mass, from crust to core. Unlike the oxygen-rich crust, the whole Earth is dominated by iron, concentrated in its dense metallic core.

✨ AI Insight

Measured as a whole planet, Earth is an iron world: iron makes up 32.1% of its total mass, narrowly ahead of oxygen at 30.1%. This is a striking reversal of the crust, where oxygen dominates and iron ranks only fourth. The difference reflects planetary structure, most of Earth's iron sank early to form the dense metallic core, while lighter, oxygen-bearing silicate minerals rose to build the mantle and crust. Silicon (15.1%) and magnesium (13.9%) are the principal mantle elements, followed by sulfur, nickel, calcium and aluminium. Just four elements, iron, oxygen, silicon and magnesium, account for over 90% of the planet's entire mass. As with the crust beneath our feet, an entire world turns out to be built from remarkably few chemical ingredients.

Source: Composition of Earth (crust to core)

Key Findings

Auto-computed highlights from this dataset

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Iron leads with 32 in All Time.

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Average value in All Time: 12 · median: 8.

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Gap in All Time: Iron is 22.9× larger than Aluminium.