The oldest rock ever found on Earth is a zircon crystal

A zircon crystal found north of Perth in 1999 has been dated to 4.374 billion years, confirming it as the oldest rock ever found on Earth. 

A tiny gem found on an outback sheep station in Western Australia has been declared the oldest known piece of our planet.

The zircon is said to be 4.4billion years old and was found by geoscience professor John Valley from the University of Wisconsin in the United States.

"It's so small you could hardly see it with a human eye. It's about the size of two human hairs," Prof. Valley said.

He was on a field trip to an area called Jack Hills about 600km north of Perth in 2001 when he found the specimen. It's an area known for its ancient gem stones which date back to when the Earth's temperatures cooled and formed a crust.

'The first 600-million years of Earth history was thought to be hell like, the surface was covered with molten rock with temperatures around 1000C,' he said.

Prof. Valley said the zircon was formed when the Earth had cooled sufficiently to form a crust.

Professor John Valley, Geoscience department, University of Wisconsin, USA

Continue reading...

Producer: Verica Jokic
http://www.abc.net.au