Zircon crystals are often tiny things that most people wouldn’t even notice if they were walking right over them.

Even when viewed under a microscope, most people would think that they are little more than a pretty crystal to look at.

To Dr. Hugo Olierook of Curtin University, however, zircons are able to reveal a lot of information about Earth from billions of years ago.

These crystals are among the oldest crystals around, and the ones that are found in Jack Hills in Western Australia, are the oldest examples of them found so far.

Some of them are an astounding 4.4 billion years old, so when geologists and other scientists got to study them, they were not disappointed.

Many of the zircons are formed in such a way as to indicate that they were in water when first made. The number of atoms in the crystals can show what type of water they were in. Dr. Olierook explains:

“When water evaporates, oxygen-16 evaporates more. It’s mostly controlled by temperatures, closer to poles it gets even lighter.”

When studied properly, the type of water can be determined, which can tell us a lot about the conditions of the planet (or at least the conditions of the part of the planet where they were formed).

Around the year 2000, the oldest information scientists had was from about 3.2 billion years ago and indicated that there was lots of water on the surface of the planet. Most experts, however, thought that prior to that, the Earth was dry.

The new information from these crystals is strong evidence that the Earth had both fresh and salt water at least 4.4 billion years ago. Dr. Olierook commented on this:

“Around the year 2000, the big theory was that 4 billion years ago the Earth was completely dry. It was desolate landscape, the sky was orange, the ground was brown. Then in 2001 evidence of water more than 4 billion years ago was found. We didn’t know the composition, but it was exciting enough to change the paradigm.”

More study is needed, and hopefully zircons (or other crystals) that are this old can be found in other parts of the world.

This would give a more complete picture of what the planet may have looked like during this period.

For now, these zircons offer valuable information that was previously hidden.

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