Rock of Ages

Crystal2

Scientists have discovered an ancient piece of the Earth on a ranch in western Australia.  Using highly specialized equipment, a team of geochemists led by John W. Valley analyzed a single grain of zircon crystal and determined that the grain is around 4.374 billion years old, give or take a few million years.  That makes this the oldest piece of the Earth ever discovered (the Earth is presumed to have coalesced around 4.54 billion years ago).  Valley and his coauthors hypothesize that this single grain formed relatively soon after some major extraterrestrial collision produced the Moon and turned the Earth’s surface into Liquid Hot Magma.  You can learn more at the links below: