The core of Uranus is often thought of as icy, but its elements are more liquid than solid. The planet's interior, which contains about 80 percent of its mass, includes methane, water and ammonia. Universe Today notes that Uranus' core is hot and dense, earning it the label "water-ammonia ocean."
The temperature of Uranus' core, at 9,000 degrees Fahrenheit, is cooler than the core temperatures of some other planets. It is believed that Uranus does have some rocky material at the center of its core. However, the fact that Uranus' core is about half the mass of Earth's core suggests the density of its rocks is minimal.