Glass is formed of sand, which contains quartz which is silica. Silica is silicon dioxide (SiO2). Silica has a very high melting point of 1700 degrees centigrade and at this temperature it is in a syrupy form.
Natural single quartz crystals consist of pure 100% silicon dioxide and are used for high quality specialty glass. Synthetic Amorphous silica also consists of almost pure quartz and has almost 100% silicon dioxide as is used to make expensive glass.
The SiO2 molecule has silicon in the centre in a tetrahedral shape and had four oxygen atoms at its four ends and is negatively charged.
Silica is mixed with lime and soda to make domestic glass which is used in the production of glass for windows, light bulbs, bottles and jars. On the other hand silica is mixed with boron oxide and soda to make thermal shock resistant glass for cooking and use in laboratories. High grade fused silica is used as such to make high thermal stability and shock resistance glass to be used in NASA space shuttles.
Natural single quartz crystals consist of pure 100% silicon dioxide and are used for high quality specialty glass. Synthetic Amorphous silica also consists of almost pure quartz and has almost 100% silicon dioxide as is used to make expensive glass.
The SiO2 molecule has silicon in the centre in a tetrahedral shape and had four oxygen atoms at its four ends and is negatively charged.
Silica is mixed with lime and soda to make domestic glass which is used in the production of glass for windows, light bulbs, bottles and jars. On the other hand silica is mixed with boron oxide and soda to make thermal shock resistant glass for cooking and use in laboratories. High grade fused silica is used as such to make high thermal stability and shock resistance glass to be used in NASA space shuttles.