Comment on 4.4 billion-year-old crystal is oldest confirmed piece of EarthparentComments−jofer12yBasically, they took chunks of what they already knew was a very old (~3.6 billion years old) rock, ground them up, separated out the zircon grains, and dated many (100's to 1000's) of individual zircon grains.
Comments
Basically, they took chunks of what they already knew was a very old (~3.6 billion years old) rock, ground them up, separated out the zircon grains, and dated many (100's to 1000's) of individual zircon grains.