The Jack Hills are a range of hills in Western Australia. They include the oldest material of terrestrial origin found on Earth. These are zircons which formed about 4.4 billion years ago (bya).[1] The oldest zircon with the most consistent date is closer to 4.35 bya.[2]
This zircon is part of a population of zircons in the metamorphosed conglomerate. They were deposited about 3.060 bya, which is the age of the youngest detrital zircon in the rock.
The zircons are used in research on the conditions on Earth in the Hadean eon.