Not that it seems that important when you are looking through it at a landscape or swilling a nice Merlot around when holding one but glass is an amorphous solid. Except it’s not a solid it’s also a liquid. Confused? Glass is both a liquid and a solid at the same time and this is why it is called amorphous because it is neither and both. We use glass in so many useful ways; it really is something of a miracle substance. Just ask Tewkesbury Double Glazing company Firmfix. If you visit Firmfix you can see the amazing things they can do with this stunning material.
Glass comes from Sand. If you heat sand to a very high temperature so that it melts it begins to do some unusual things. First of all it becomes molten and with careful handling you can shape it into any shape that you want using molds or in the old fashioned manner of the glass blower. Here air was literally blown into the molten glass to make bowls and glasses.
As the sand cools it takes on a clearness as opposed to the original opaqueness. The key to the change is the heat. However, the sand is no longer a solid even when it is cooled and “solid”. It is actually still a liquid but one that is firm to touch.The molecules, like in a liquid, are still moving only very very slowly and held together by the atoms within the structure. The best way to describe it is that it is like Ice that never melts. It’s still water, but now it’s solid.
How ordinary glass is made from sand
Glass is made from sand. Common sand, which is mostly silicon dioxide, melts only at extreme temperatures of over 1600°C. When this molten sand cools, it does not turn back into grains. Its inner structure changes completely, and however far it is cooled it never sets into a true crystalline solid. Instead it becomes a kind of frozen liquid, the amorphous solid that gives glass its unusual nature.
Commercially, sand is mixed with recycled glass, soda ash and limestone and heated in a furnace. Soda ash lowers the melting point of the sand, which saves energy, but on its own it would produce glass that dissolves in water. Lime is added to prevent this, and the result is soda lime silica glass, the ordinary glass seen all around us.
Glass is so common because it is transparent, cheap to make, easy to shape while molten, fairly heat resistant once set, chemically inert and can be recycled again and again.