Scientists Unearth World's Oldest Rock: 4.4 Billion-Year-Old Crystal

The secrets of early Earth lie in a bright red crystal no larger than a dust mite

A group of scientists claim to have dated a 400-micrometer zircon crystal to about 4.4 billion years ago — a discovery that could help scientists understand the geological conditions of early Earth.

The crystal was found in a region north of Perth, Australia known as the Jack Hills in 2001, Reuters reported. The scientists published their findings in the science journal Nature Geoscience on Feb. 23; in the publication, Valley and his team explained their use of a technique called atom-probe tomography to date the crystal. The technique allows scientists to image and assess single atoms of lead to determine the age of a rock with increased accuracy. Read more...