How do diamonds form?
There are four processes that are thought responsible for virtually all the natural diamonds found on earth's surface.
Diamond formation on the Earth's mantle
Deep Source Eruption Geologists believe that all the diamonds in the commercial diamond deposits of Earth have been formed in the mantle and came to the surface by deep- source volcanic eruptions. Continental Plate Upper Mantle Diamond Stability Zone
Diamond formation in the subduction zones
Tiny diamonds have been found in rocks that are thought to have been subducted deep into the mantle by plate tectonic processes - then returned to the surface. Oceanic Plate Continental Plate Upper Mantle Subduction Zone
Diamond formation at im impact sites
4 Deep Source Eruption Meteorite Fall Asteroid Impact Oceanic Plate Continental Plate Upper Mantle Subduction Zone Diamond Stability Zone When these asteroids strike the earth, extreme temperatures and pressures are produced The high temperature and pressure conditions of such an impact are more than adequate to form diamonds. This theory of diamond formation has been supported by the discovery of tiny diamonds around several asteroid impact sites
Diamond formation in space
4 Meteorite Fall NASA researchers have detected large numbers of nanodiamonds in some meteorites About three percent of the carbon in these meteorites is contained in the form of nanodiamonds Continental Plate Upper Mantle