So no one knows for sure, however recently some scientists at the Lawrence Livermore National Laboratory provided compelling evidence that oceans made of diamond, complete with icebergs (diamondbergs?) may exist in our own solar system. The pressure near the more solid part of Uranus and Neptune is millions of times stronger than our own atmosphere and the heat is through the roof, so to speak, all of which makes it incredibly difficult to actually observe a diamond ocean.

From Discovery:

Eggert and his colleagues took a small, natural, clear diamond, about a tenth of a carat by weight and half a millimeter thick, and blasted it with lasers at ultrahigh pressures like those found on gas giants like Neptune and Uranus.

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.

Diamond Oceans Possible on Uranus, Neptune

Diamondbergs, Diamonds, Neptune, ocean, Science, Solar System, Space, Uranus