What is geochemistry?

The term Geochemistry is obtained from the etymological term Geo + Chemsitry, which means Earth and chemical principles.

Thus Geochemistry is that branch of Science which applies chemical principles to understand the Earth system. This principle is used to explain the mechanism behind the major geological systems such as Earth’s crust, oceans, biosphere and climate, rocks, fluids, gases and biological reactions, that exchanges matter and energy over a range of time scale.

Geochemistry integrates the principle of physics, chemistry and biology to study the dynamics and processes of the earth.

Furthermore, the study extends beyond the Earth, encompassing the entire Solar system, i.e. in the study of other planet, origin of granite, study of sun etc.

Subfields of geochemistry

The various subfields of Geochemistry is as follows-

  • Biogeochemistry
  • Organic geochemistry
  • Trace & Elemental geochemistry
  • Metamorphic & Igneous-rock geochemistry
  • Regional Geochemistry
  • Photogeochemisty etc.

Earth’s Mineral Constitution

Our planet houses about 94 elements which are naturally occurring. These elements are not found in their simple elemental states. They are generally combined with other other elements and need to be separated if we wish to use them for any intended purpose.

Most of the substances are present in the form of compounds of oxygen, chlorine, sulphur, and fluorine.

Percentage of composition of materials on the earth has been found to be:


Percentage of composition on earth’s crust (%)

Si O2


Al2 O3


Fe2 O3


Fe O


Mg O


Ca O


Na2 O


K2 O


H2 O


Ti O2


P2 O5


Incorporating the concepts of other sciences like geobiology, geophysics and geology, geochemistry is used to find how different factors of the metamorphic and igneous processes like rates and timings are on the different planets in our solar system.