Abundances of the Elements in the Earth's Crust

Element

Approximate % by weight

Oxygen

46.6

Silicon

27.7

Aluminum

8.1

Iron

5.0

Calcium

3.6

Sodium

2.8

Potassium

2.6

Magnesium

2.1

All others

1.5

Element

Symbol

percent mass

Oxygen

O

65.0

Carbon

C

18.5

Hydrogen

H

9.5

Nitrogen

N

3.2

Calcium

Ca

1.5

Phosphorus

P

1.0

Potassium

K

0.4

Sulfur

S

0.3

Sodium

Na

0.2

Chlorine

Cl

0.2

Magnesium

Mg

0.1

All others

< 0.1