Love inside this Diamond!

While most diamonds are paired with deep looks of love, one diamond discovered in Botswana has delivered a deep look into planet Earth. To the average eye, the little black specks contained within this green octahedral diamond are nothing more than undesirable inclusions and flaws. But to Cal Tech mineralogist, George Rossman, who purchased the diamond in 1987, they represent an exciting discovery— a new mineral dubbed davemaoite. This find provides a hint of the mineralogical environment of deep Earth.

Davemaoite (named for Ho-kwang “Dave” Mao, who has made pioneering discoveries in high-pressure mineralogy) formed at high temperature and high pressure deep below Earth’s surface. Previously, it had only been produced in the lab, but according to a team led by geochemist, Oliver Tschauner, of the University of Nevada, Las Vegas, this marks the first time a specimen has been found in nature. Davemaoite offers “a rare glimpse of something that normally cannot exist on Earth’s surface,” per a recent report by publishers of the journal Nature. It provides rare clues about heat flow deep in the lower mantle of Earth in a region between the planet’s crust and core where direct sampling is inaccessible.

Per Tschauner, these little black specks survived a journey to Earth’s surface because of “the strength of the diamond that keeps the inclusions at high pressure.” Such deep-Earth diamonds are now viewed as important portals to give us vital clues as to the geology, geochemistry and geophysics deep down beneath our feet.