Just like in the previous picture, we can see a diagram of the structure of SiO2. Again, we can see how the molecules combine to form a network of repeating hexagons. Even though it is not shown in the picture, the angles between one Si atom and one O atom are 110 degrees. Being that when the molecules are connected, one Si is being bonded by four Oxygen molecules. An explanation to how Si and O are bonded is shown in the YouTube video below.
Molecular Structure of SiO2
In the picture to the right, we can see the molecular structure of quartz. For the key, each blue dot is Oxygen (O) while each red dot is Silicon (S). In this picture you can see how the Silicon and Oxygen bond together. Two oxygen atoms are bonded together by one silicon atom in the middle. They are bonded by covalent bonding.