Silicates are minerals that contain silicon atoms bonded to oxygen atoms. The basic building block for all silicate minerals is called a tetrahedron, where one silicon atom is bonded to 4 oxygen atoms (Figure 3.6). Silicate minerals also often contain other elements, such as calcium, iron, and magnesium.hosphates have a tetrahedron building block that is similar to that of the silicates. But, instead of silicon, phosphates have an atom of phosphorus, arsenic, or vanadium bonded to oxygen. Although there are many minerals in this group, most of the minerals are rare.
Neptune is the coldest planet in the Solar System. At the top of its clouds, temperatures on Neptune can dip down to 51.7 Kelvin, or -221.4 degrees Celsius. Thatâs cold! Pluto gets colder, but then, Pluto isnât a planet any more.
Like Earth, Neptune has a rocky core made up of iron and other metals, with a mass just greater than our planet. Temperatures in the core could reach 9,260 F (5,127 C). Strange rings. Like the other gas giants, Neptune boasts a series of rings. But the blue planet's six rings are not as solid as its neighbors. Instead, the clumpy rings contain prominent arcs, likely due to the influence of one of Neptune's moons. Made up of ice particles and silicates, the rings are reddish. Neptune's rings were first discovered when it passed between a star while astronomers were attempting to study the planet. The star faded out, then returned to view.