{"id":36113,"date":"2026-09-01T15:00:00","date_gmt":"2026-09-01T19:00:00","guid":{"rendered":"https:\/\/www.ecoticias.com\/en\/?p=36113"},"modified":"2026-09-01T06:31:07","modified_gmt":"2026-09-01T10:31:07","slug":"a-zircon-grain-found-in-western-australias-jack-hills-is-4-4-billion-years-old-making-it-the-oldest-known-terrestrial-mineral-grain","status":"publish","type":"post","link":"https:\/\/www.ecoticias.com\/en\/a-zircon-grain-found-in-western-australias-jack-hills-is-4-4-billion-years-old-making-it-the-oldest-known-terrestrial-mineral-grain\/36113\/","title":{"rendered":"\ufeffA zircon grain found in Western Australia\u2019s Jack Hills is 4.4 billion years old, making it the oldest known terrestrial mineral grain"},"content":{"rendered":"\n

A tiny remnant of a 4.4-billion-year-old crystal was discovered in the Jack Hills in Western Australia<\/a>. The find corresponds to a 2025 lunar study<\/a>, which dates the Moon\u2019s final solidification phase back to roughly the same era.<\/p>\n\n\n\n

The solar system\u2019s tumultuous beginnings have another piece of solid evidence. The corresponding estimated window is broad, but the dust-mite-sized specimen from early Earth<\/a> probably formed in the same space of time when the Moon was crystallizing into what we see in the sky today.<\/p>\n\n\n\n

A crystal older than continents<\/h2>\n\n\n\n

In 2001, scientists used uranium-lead geochronology<\/a> to determine the zircon\u2019s age. The estimation was later confirmed in 2014, using atom-probe tomography to erase concerns that lead movement inside the specimen could have affected the accuracy of the measurement.<\/p>\n\n\n\n

The tiny grain, only 4 mm across, is made of a material resistant to erosion or chemical change, allowing it to last through Earth\u2019s violent beginnings. Almost impervious to melting or burial, it managed to remain preserved in its original state through billions of years.<\/p>\n\n\n\n

\"Jack
Metasedimentary rock from Western Australia’s Jack Hills contains tiny zircon grains, some of which have been dated to about 4.4 billion years ago.<\/figcaption><\/figure>\n\n\n\n

Signs of an early ocean<\/h2>\n\n\n\n

Analysts determined that the material must have been in contact with cold water before the crystal formed, according to its oxygen isotope chemistry<\/a>. This offers the earliest evidence to date of the Earth\u2019s continental crust and ocean formation.<\/p>\n\n\n\n

The popular image of the Hadean world\u2013a hellish, molten Earth lasting 600 million years, was now in doubt. The finding suggests that surface water<\/a> and solid rock may have formed only 100 to 200 million years after the Earth\u2019s formation, earlier than previously accepted.<\/p>\n\n\n\n

The Moon was still hardening<\/h2>\n\n\n\n

The popular explanation for the Moon\u2019s birth was due to a violent collision between young Earth<\/a> and a projectile the size of Mars. The impact produced a celestial body covered by an ocean <\/a>of molten rock, which eventually cooled and crystallized.<\/p>\n\n\n\n

The 2025 study measured radioactive decay in lunar zircons brought back from the Apollo missions<\/a>. They concluded that the magma ocean on the Moon was over 90% crystallized around 4.43 billion years ago, give or take 76 million years.<\/p>\n\n\n\n

Two clocks from the same era<\/h2>\n\n\n\n

A previous lunar study<\/a> identified a zircon dating back 4.417 billion years, considered the likely time of the magma ocean crystallization. The Jack Hills grain is 13 million years earlier, while the 2025 estimate pre-dates that one by another 12 million years, both blinks of an eye in the scale of the universe.<\/p>\n\n\n\n

Researchers cannot be sure if there is a direct connection, but there is certainly compelling evidence that the Moon and Earth surfaces were cooling in around the same geological era.<\/p>\n\n\n\n

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