GLASS

Glass is an amorphous solid material that exhibits a glass transition, which is the reversible transition in amorphous materials from a hard and relatively brittle state into a molten or rubber-like state. 

Glasses are typically brittle and can be optically transparent.

THE BIZARRE PROPERTIES OF GLASS

IS IT A SOLID OR A LIQUID?

Despite the solid appearance, glass is actually in a ‘jammed’ state of matter.

It is somewhere between liquid and solid.

It has random un-oriented molecules as opposed to a crystal solid with arranged fixed molecules.

It moves very slowly and never quite becomes a proper solid.

HOW GLASS IS MADE….?

Glass is a made by melting a mixture of sand and other minerals in a furnace at temperatures of 1700º Celsius (3,092º F).

Silica in the form of sand is the main ingredient of glass, and this is combined with soda ash and limestone in special pots which are placed into the furnace.

Broken, recycled glass known as 'cullet' is added to the ingredients to speed up the melting process.

Other materials can be added to produce different colours or properties. For example, adding the minerals cobalt or sulphur will produce coloured glass.

Glass has been made since the times of the Ancient Egyptians, about 3000 years ago. The Egyptians made glass beads and used them as jewellery.

Roman Cage Cup from the 4th century AD Ancient Greek glass amphora from the Hellenistic period.

Some other things made with glass

Aquariums

Engraved glassware

Test tubes

Stained glass window panels

Also used in making mirrors, ornaments, car windsheilds, building exteriors and interios etc.,

Naturally formed glass

Obsidian is a naturally formed glassy stone. It forms when sand shoots out of an erupting volcano. It melts in the volcanic lava and when it comes into contact with water it cools quickly. The glass is dark green to black. Obsidian has been used by ancient peoples since the Stone Age, as a cutting tool, for tips for spears, and for ceremonial purposes.

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