The info related to the title is buried in the middle of the article. For those who don't have patience.. ..Uranus and Neptune must contain vast quantities of

The info related to the title is buried in the middle of the article. For those who don't have patience.. ..Uranus and Neptune must contain vast quantities of water, ammonia, and methane on the inside.. He finds that the carbon atoms spontaneously break free of their molecules and arrange themselves into diamonds. Inside Uranus and Neptune, such diamonds could grow to the size of a person, slowly raining down toward the core of the planet..