4.25 billion year old diamond discovered
mongabay.com
August 22, 2007
Scientists have discovered 4.25 billion year old diamonds in Australia.
The diamonds, found trapped in zircon crystals in Western Australia, are the oldest identified fragments of the Earth’s crust. Their existence suggests that Earth may have cooled faster than previously believed, said researchers led by Martina Menneken of Westfalische Wilhelms-Universitat Muenster, Germany.
“These latest findings indicate that the planet was already cooling and forming a crust much earlier than previously thought,” said Alexander Nemchin, a geochemist at Australia’s Curtin University of Technology and a co-author of the study, published in Nature.
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Simon Wilde, a geologist at Curtin University of Technology in Perth, told Reuters that zircon crystals represent the only record of the first 400 million to 500 million years of Earth’s history. The presence of diamonds — which form under intense pressure and temperatures — within this mineral implies that Earth already featured a thick continental crust 4.25 billion years ago, earlier than conventionally held.
The diamonds are about 1 billion years older than the previous oldest-known diamonds.
This article is based on a report from Reuters and a news release from Curtin University.