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"A tiny zircon crystal from Australia, 4.4 billions years old, has been confirmed as the oldest discovered fragment of Earth's crust, scientists say."^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.upi.com/Science_News/2014/02/24/Oldest-known-fragment-of-Earths-crust-suggests-early-cooling/UPI-81581393273434/>