There’s diamonds in them thar planets

Are you are a budding imperial overlord and have just taken purchase of your own Space Shuttle? Is threatening to level New York just too passé? Well it may need a few extra engines and a big oxygen tank but there may be treasure a plenty out in the outer solar system.
According to a new study published by Nature there may be diamond oceans filled with solid diamond icebergs, could be floating on Neptune and Uranus.

The research is based on the first detailed measurements of the melting point of diamond. It found diamond behaves like water during freezing and melting, with solid forms floating atop liquid forms.

"Diamond is a relatively common material on Earth, but its melting point has never been measured," says Dr Jon Eggert of the Lawrence Livermore National Laboratory in California. "You can't just raise the temperature and have it melt; you have to also go to high pressures, which makes it very difficult to measure the temperature."

The scientists liquefied the diamond at pressures 40 million times greater than what a person feels when standing at sea level on Earth. From there they slowly reduced the temperature and pressure.

When the pressure dropped to about 11 million times the atmospheric pressure at sea level on Earth and the temperature dropped to about 50,000 degrees solid chunks of diamond began to appear. The pressure kept dropping, but the temperature of the diamond remained the same, with more and more chunks of diamond forming. But the diamond did something unexpected.
The chunks of diamond didn't sink. They floated. he diamond was behaving like water.

An ocean of diamond could help explain the orientation of the planet's magnetic field as well, says Eggert. Roughly speaking, the Earth's magnetic poles match up with the geographic poles. The magnetic and geographic poles on Uranus and Neptune do not match up; in fact, they can be up to 60 degrees off of the north-south axis. A swirling ocean of liquid diamond could be responsible for the discrepancy.

I have no idea if this is a load of hooey but the idea of diamond icebergs... well it could go a long way to funding the intergalactic empire of your dreams!

Diamonds are forever or at least a very long time

A clutch of ancient diamonds found in Western Australia have been identified as the oldest remnants of the Earth's crust ever recovered.

The stones, which are over 4bn years old, were found inside rocks lodged in the sediments of a coastal ridge known as the Jack Hills. It is hoped that they will shed light on the earliest period of the Earth's history, the Hadean period (the period between the planet's initial formation and the formation of the first rocks.). The oldest of the diamonds is thought to be 4.25bn years old. This would suggest that the Earth had cooled enough to form a crust of solid rock by that time, earlier than originally thought.

This is definitely in the “fascinating stuff” category. Geology isn’t my area of expertise (try mammalian physiology and microbiology, although university is a long time ago now...)