It's very clear that glass is an important part of our everyday lives. From the glass we drink water in, to the spectacles we wear, to window panes; glass is just everywhere.
Here, there and everywhere
Windscreens of cars, windows in houses, furniture, television sets and soft drink bottles - all are made of glass. Did you know the first glass was from ancient Mesopotamia and Egypt? What's more, glass even forms in nature. Lighting hits a sand dune forming a lump of raw glass. Molten lava cools and forms raw glass. In ancient days, this natural raw glass was used as weapons, cutting tools and ornaments.
The first glass
The story of glass begins in ancient Egypt where glass-making became popular during the late Bronze Age. Some of the earliest objects made of glass were glass beads for jewellery followed by coloured glass vessels. Glass-making has not changed since these early days.
Ancient Egyptians were one of the first people to make glass.
What is glass made of?
Glass consists of 70% silica, a compound of sand. Various other substances are mixed with Silica to form glass. For example, a mixture of raw sand and Sodium Carbonate helps in reducing the melting point of silica. Calcium Oxide, Magnesium Oxide and Aluminium Oxide give better chemical durability. Calumite, a by-product of the iron industry and a recycled glass called Cullet are also used. This basic mixture is melted and cooled in a controlled environment to make glass.
Special types of glass
A range of special varieties of glass can be made by varying the ingredients slightly. If you want to make a glass that is more sparking, then you add Lead Oxide crystal or flint glass instead of lime. This increases the sparkle, creating crystal glass.
Boric Oxide makes glass ideal for baking, microwaves and lab equipment. And did you know that for fibre optic cables that carry digital information, glass is made of pure silica! Here, the clarity of the glass is critical for quickly transferring information using photonic signals.