A 4 billion-year-old crystal that was recently found in Australia has been confirmed as the oldest known piece of Earth that has ever been recovered. This ancient stone is a true gem in all senses of the word, as world experts used two proven age-determining techniques to verify that a zircon crystal recently uncovered at a sheep ranch dates back to over 4.4 billion years ago. CBS News reports this Monday, Feb. 24, 2014, that the incredibly rare find suggests that the old world may not have been as harsh as once thought.
As a gem for the ages, this 4 billion-year-old crystal tells scientists today quite a bit about what Earth was like all those many years ago. The amazing find was discovered on a sheep ranch located in far western Australia, and has since been reliably shown to be the very oldest “stone” that still exists today from ancient history.
"This is the oldest reliably dated piece of the Earth that we have, that anyone knows of," John Valley told a news station in excitement.
John Valley served as the leader of the research team and a professor of the geosciences from the University of Wisconsin. He said that the team’s find of the crystal suggests that the Earth’s crust was formed only shortly after the planet itself was “created,” and this bluish stone is a tiny memory from that distant period in the world.
In order to confirm the historic age of this 4 billion-year-old crystal, the zircon fragment underwent a number of tests. Earth scientists’ main method was a widely approved of dating technique that determines a stone’s age through the radioactive decay levels of uranium that ultimately lead to a mineral sample.
A second test was then performed on the piece, which corroborated that this historic zircon crystal’s find is indeed a true gem. A novel technique called atom-probe tomography was used, which has the incredible ability to identify particular atoms of lead in a crystal sample, and from that ascertain their mass in terms of age. The findings? Yes, this stone is truly 4.4 billion years old.
While this number might seem impossible to even think about, a perspective of this historic period is possible. The Earth was only formed 4.5 billion years ago, little more than a giant sphere of molten rock. Less than 100 million years later, the planet’s crust began to form on the outside of this molten mass. The crystal’s ancient age suggests that the crust formed roughly 160 million years after the solar system’s formation.
Valley concluded his report in noting that the discovery of this blush crystal points to the idea that early Earth may not have been as harsh as once expected, and Earth likely had liquid water as early as 4.3 billion years ago. This would have allowed Earth to sustain minute forms of life, namely microbial existence.