A 4.4bn-year-old zircon crystal has been confirmed as the oldest known piece of the Earth.
Two different dating techniques were used to test the tiny mineral fragment from sandstone deposits in the Jack Hills region of western Australia.
Scientists believe the crystal is evidence that the Earth’s crust was created relatively soon after the planet formed from gas and dust swirling round the Sun.
Around 4.5bn years ago, the Earth is believed to have been a fiery ball of molten rock.
The great age of the zircon supports theories of a “cool early Earth”, with temperatures quickly falling low enough to permit oceans and perhaps even life.
Scientists led by Professor John Valley, from the University of Wisconsin, US, used two kinds of dating technique to rule out the possibility of a false result.
The findings appear in the latest edition of the journal, Nature Geoscience.
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