Blue Rocks Posted on February 24, 2014 by michelledevilliersart Blue Rocks! H/T to Ze Finger of ZirCon and the Hadean. Related articles Jack Hills Zircon: Scientists Discover Oldest-Known Fragment of Earth 4.4 billion-year-old crystal points to chill early Earth Minerals Present When Life Emerged in Hadean Eon Vastly Different Than Today Tiny zircon crystal is oldest piece of Earth ever found: scientists Rock around the clock: zircon crystal is oldest piece of Earth 4.4 bn year old zircon reveals life on Earth appeared earlier than believed