Relative Abundance of the Chemical Elements in the Earth System

Taken as a whole, Earth's chemical composition (by mass) is:

34.6% Iron
29.5% Oxygen
15.2% Silicon
12.7% Magnesium
2.4% Nickel
1.9% Sulfur
0.05% Titanium

The "Big Eight", which account for ~99% of the material in the Earth System:

Element
% by Weight
of Earth System
46.6
27.7
8.1
5.0
3.6
2.6
2.6

The Rest of the "Top Twenty" elements, in terms of their relative presence in the Earth System: