Zircon crystal found in Australia oldest known piece of Earth

To put it mildly, this is one gem of a gem.

Scientists using two different age-determining techniques have shown that a tiny zircon crystal found on a sheep station in western Australia is the oldest known piece of our planet, dating to 4.4 billion years ago.

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I first heard about ancient zircons quite a few years ago, ten years ago?

The Zircons at “4.374 billion years” is extremely old for any Earth rock. Compare with the following.

Late heavy bombardment (that formed the Moon’s Craters) was 4.1 to 3.8 billion years ago.
Lunar anorthosite 4.29 to 4.54 +- 0.11 billion years ago.
The Moon is 4.527 billion years old.
The Solar System is 4.568 billion years old.

mollwollfumble said:

I first heard about ancient zircons quite a few years ago, ten years ago?

The Zircons at “4.374 billion years” is extremely old for any Earth rock. Compare with the following.

Late heavy bombardment (that formed the Moon’s Craters) was 4.1 to 3.8 billion years ago.
Lunar anorthosite 4.29 to 4.54 +- 0.11 billion years ago.
The Moon is 4.527 billion years old.
The Solar System is 4.568 billion years old.

Large sections of Western Australia comprise rocks that are around 2.8-3 billion years old. The Yilgarn Craton. The zircons were found within part of this.

morrie said:

mollwollfumble said:

I first heard about ancient zircons quite a few years ago, ten years ago?

The Zircons at “4.374 billion years” is extremely old for any Earth rock. Compare with the following.

Late heavy bombardment (that formed the Moon’s Craters) was 4.1 to 3.8 billion years ago.
Lunar anorthosite 4.29 to 4.54 +- 0.11 billion years ago.
The Moon is 4.527 billion years old.
The Solar System is 4.568 billion years old.

Large sections of Western Australia comprise rocks that are around 2.8-3 billion years old. The Yilgarn Craton. The zircons were found within part of this.

Eroded from older rocks?

roughbarked said:

morrie said:

mollwollfumble said:

I first heard about ancient zircons quite a few years ago, ten years ago?

The Zircons at “4.374 billion years” is extremely old for any Earth rock. Compare with the following.

Late heavy bombardment (that formed the Moon’s Craters) was 4.1 to 3.8 billion years ago.
Lunar anorthosite 4.29 to 4.54 +- 0.11 billion years ago.
The Moon is 4.527 billion years old.
The Solar System is 4.568 billion years old.

Large sections of Western Australia comprise rocks that are around 2.8-3 billion years old. The Yilgarn Craton. The zircons were found within part of this.

Eroded from older rocks?

Yes. Being hard, the zircons survived the erosion when less stable minerals didn’t.