  Komatiites are fascinating volcanic rocks. They are among the most ancient
lavas of the Earth following the 3.8 Ga pillow basalts at Isua and they
represent some of the oldest ultramafic magmatic rocks preserved in the Earth's
crust at 3.5 Ga. This fact, linked to their particular features (high magnesium
content, high melting temperatures, low dynamic viscosities, etc.), has
attracted the community of geoscientists since their discovery in the early
sixties, who have tried to determine their origin and understand their meaning
in the context of the terrestrial mantle evolution. In addition, it has been
proposed that komatiites are not restricted to our planet, but they could be
found in other extraterrestrial setting in our Solar System (particularly in
Mars and Io). It is important to note that komatiites may be extremely
significant in the study of the origins and evolution of Life on Earth. They
not only preserve essential geochemical clues of the interaction between the
pristine Earth rocks and atmosphere, but also may have been potential suitable
sites for biological processes to develop. Thus, besides reviewing the main
geodynamic, petrological and geochemical characteristics of komatiites, this
paper also aims to widen their investigation beyond the classical geological
prospect, calling attention to them as attracting rocks for research in
planetology and astrobiology.
