Diamonds Almost Forever

Diamonds almost as old as the Earth itself have been found locked in ancient crystals of zircon from the Jack Hills region of Western Australia, according to scientists writing in Nature this week. The diamonds could provide unique insights into the early evolution of our planet’s crust.

Zircons are tough and resist heat and some samples have been shown to be several billion years old. As such, they retain vital clues about the Earth’s geological evolution, at least as far as the crust and mantle are concerned. Recent studies of these ancient crystals have suggested that the Earth may have cooled much faster than previously thought, with the continental crust and oceans forming some 4.4 billion years ago.

Now, Martina Menneken and colleagues at the Westfaeische Wilhelms-Universitaet Muenster, in Germany, have investigated mineral inclusions within zircons and found that some of them contained small diamonds. The zircons have been dated using uranium and lead isotopes and found to be over four billion years old,” almost one billion years older than the previous oldest-known terrestrial diamonds, and present in material that crystallized within 300 million years of the formation of the Earth itself.

The authors suggest that these diamond inclusions formed under ultrahigh-pressure conditions, which implies that the Earth had a relatively thick continental crust and crust-mantle interaction at least 4.25 billion years ago. Diamonds are formed in the earths interior, where they are brought to the surface by volcanoes and it is known as one of the hardest materials on earth.

Author: 雷竞技官网

Award-winning freelance science writer, author of Deceived Wisdom. Sharp-shooting photographer and wannabe rockstar.