The oldest bits on earth
June 5, 2006 Leave a comment
Did you know that Zircon is the oldest known material on earth? I didn’t. Scientists discovered bits of Zircon in Western Australia that are 4.404 billion years old. The Earth formed a scant 150 million years prior to that. Older bits were discovered in a meteorite in Chile, clocked at 4.6 billion years old.
How can this be? From the article:
Zircon contains its own internal atomic clock. Its crystal accumulates atoms of uranium, which decay to lead at a known rate. By measuring the relative abundance of two types of uranium and lead in a zircon, geologists can determine old it is. Zircon is also incredibly durable. It remains unscathed while other rocks and minerals melt and re-form under the tremendous heat and pressure of continental shifts, mountain-building, and violent asteroid impacts.
In fact, like most of us, I assumed Cubic Zirconia (imitation diamonds) were derived from Zircon. They’re not. The cubic variety is laboratory-grown for your inexpensive pleasure.