what is the earth made of?

Earth is mostly rock and metal, arranged in layers: a thin rocky crust, a thick rocky mantle, and a metallic core of iron and nickel, plus a thin blanket of air and a surface layer of water.

Big picture: what Earth is made of

As a whole, Earth is dominated by iron , oxygen, silicon and magnesium, with smaller amounts of elements like sulfur, nickel, calcium and aluminum.

Almost all of that material is solid or very hot, soft rock, with liquid metal in the outer core and liquid water at the surface.

Scientists often talk about two ways of “what Earth is made of”:

By layers (crust, mantle, core).
By elements (which chemical elements are most common).

Earth’s main layers (simple tour)

Imagine cutting Earth like an onion: you’d see several layers, each made of different stuff.

Crust (the skin we live on)
- Thin, solid rock layer on the outside.

 * Two types:
   * Continental crust: mostly light rocks like granite and many sedimentary and metamorphic rocks.

   * Oceanic crust: darker, denser basaltic rock under the oceans.

 * Made largely of “silicate” minerals (compounds of silicon and oxygen) with aluminum, iron, calcium, sodium, potassium and magnesium.

Mantle (the thick rocky middle)
- Makes up most of Earth’s volume and mass.

 * Composed of dense, ultramafic rock such as peridotite, rich in silicate minerals containing magnesium and iron (like olivine and pyroxene).

 * Mostly solid, but so hot it can slowly flow over long times, driving plate tectonics.

Core (the metallic heart)
- Mostly iron with some nickel, plus a little sulfur and other light elements.

 * Two parts:
   * Outer core: liquid metal, whose motion generates Earth’s magnetic field.

   * Inner core: solid ball of iron–nickel alloy under immense pressure.

Outside and on top:

Oceans : a thin layer of liquid, salty water covering most of the crust.

Atmosphere : a gas layer of mainly nitrogen and oxygen, with trace gases like argon and carbon dioxide.

What elements is Earth made of?

If you could melt Earth and mix it completely, its overall elements by mass would be roughly:

Iron – about one‑third of Earth’s total mass.

Oxygen – about one‑third.

Silicon – about one‑seventh.

Magnesium – a bit less than silicon.

Smaller amounts: sulfur, nickel, calcium, aluminum, and many trace elements.

In the crust specifically, the most abundant elements are:

Oxygen
Silicon
Aluminum
Plus iron, calcium, sodium, potassium and magnesium making up most of the rest.

Layer vs. element view (quick table)

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Part of Earth	What it is mostly made of
Crust	Light silicate rocks (granite, basalt), rich in oxygen, silicon, aluminum, plus other metals.
Mantle	Dense silicate rock (peridotite) containing magnesium and iron silicates.
Outer core	Liquid iron–nickel alloy with some lighter elements like sulfur.
Inner core	Solid iron–nickel alloy, extremely hot and dense.
Oceans	Liquid water with dissolved salts (mainly sodium and chloride).
Atmosphere	Gases: mostly nitrogen and oxygen, with argon and carbon dioxide.

How we know, and what people discuss

Scientists cannot drill to the core, so they infer Earth’s inner composition from:

Seismic waves from earthquakes (how they travel through Earth).
Meteorites (leftovers from early Solar System building blocks).
Gravity and magnetic field measurements, plus lab experiments on rocks at high pressure.

There are still active debates and forum discussions about details, such as exactly which light elements are mixed into the core, or how much of certain elements (like sulfur or silicon) it contains. But the overall picture—rocky mantle and crust around an iron‑nickel core, with water and air at the surface—is very well established.

Information gathered from public forums or data available on the internet and portrayed here.