zircon.

[hallow]

I just purchased a jack hill zircon, does anyone know more about this crystal? All i know about it, that's its extremely old. Any information would be great. Thanks!

[Azmond]

Originally Posted by hallow

I just purchased a jack hill zircon, does anyone know more about this crystal? All i know about it, that's its extremely old. Any information would be great. Thanks!

Not extremely old, but supposedly the oldest earth materials discovered.

"A zircon from the Jack Hills in Western Australia was claimed to be 4.4 billion years old13, but the age has proven contentious and is thought to reflect post-crystallization modification. Valley et al.12 use atom-probe tomography to map the distribution of radiogenic lead isotopes at a nanometre scale. They show that although the lead isotopes can be mobile and form discrete clusters within the mineral grain, the heterogeneity occurs on such a small scale that it will not affect current dating techniques. The analyses confirm that the oldest known zircon on Earth 4.374 ± 0.006 billion years old. The grain is probably less than 100 million years younger than the Earth–Moon system and is likely to be a remnant of the oldest continental crust."

If you believe that they can measure something so precisely, and of course if you believe that we actually know how old the Earth is.

[hallow]

Wow! Thank you.