Diamonds In Meteorite May Come From ‘Lost’ Planet

A meteorite with unusual composition may provide valuable insights into the early history of our solar system.

The meteorite, first discovered in 2008, belongs to a rare category of space rocks called ureilites. Compared to other meteorites, these contain a large amount of graphite and diamond.

An analysis of this particular meteorite’s diamonds revealed that they are full of inclusions, or tiny imperfections, that provide clues about the gems’ origins.

A transmission electron microscopy image of one of the diamonds recovered from the meteorite

Here’s Nicholas St. Fleur, reporting for The New York Times:

“What for a jeweler is an imperfection becomes for me something that is very useful because it tells me about the history of the diamond,” said Dr. Gillet, [an author of the paper that was published in Nature Communications]. “It has a chemistry which has no equivalent in the solar system today, in terms of planets,” he said.

The unique composition of the meteorite suggests that it is about 4.5 billion years old and hails from a time when protoplanets, or planets in their early stages of evolution, orbited our sun. These protoplanets collided with one another to form the planets of our current solar system.

Dr. Gilbert and his team believe that the meteorite traces its origins back to when a protoplanet collided with another planet. The collision produced debris that remained in space for billions of years before falling to Earth.

The rock’s special chemistry isn’t the only reason scientists are excited. It also contains the largest meteorite diamonds ever discovered.

The authors of the paper pointed out that diamonds of this size and composition could only be created under extreme pressure. They concluded that the diamonds formed under 20 giga-pascals, about 200,000 greater than atmospheric pressure at sea level.

These conditions could only be achieved inside a planet the size of Mercury or Mars, providing more evidence that the meteorite comes from a ‘lost’ planet.