Either this article is stupid, or I am, and I don’t rule out myself!
A diamond is carbon, right? Pure carbon? Carbon melts at high temps? How are such high temps generated so far away from the sun?
Couldn’t we say that the Earth is chock full of diamonds? Coal is carbon, just like diamonds.
Materials behave very differently at extremes of temperature and pressure. While Uranus may be far from the sun, the vast pressure of its gaseous atmosphere might mean that the melting point of the crystalline form of carbon is at a much lower temperature than here on Earth.
My guess is the diamonds would be found under Uranus’s thick atmosphere which would be a high pressure and temperature environment.
“How are such high temps generated so far away from the sun?”
The spinning motion of gas giant planets such as Uranus and Neptune generates a lot of energy. Combine that with their immense gravitational fields and the result is the ability to create areas of extreme temperature and pressure.
Graphite and diamond molecules are both 100% carbon. The difference is the manner in which the carbon atoms within the molecules are arranged.
Atmoshperic pressure.