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.
Neptuneâs vibrant blue color looks spectacular when observed with a powerful telescope. With a mass of 1.02 x 1026 kg, it is 17 times heavier than Earth. Around 11 known satellites orbit Neptune, but the planetâs largest moon Triton has a retrograde orbit, i.e. it orbits in a direction opposite to Neptuneâs rotation.o, when we see the bright bluish color of Neptune, we actually see the reflected sunlight, minus the red light. Neptune looks like a beautiful blue sphere from a distance, but the color variations in its clouds can be clearly noticed, if viewed closely. The surface of Neptune is also well-known for powerful storms.