The main raw material to produce glass is silicon. Silicon is present in nature inside sand and in some compact rocks (quartzites). The sands that are used are very pure and fine. The materials, pulverized, are heated at 1200 – 1400 °C for a few hours. Then, after a slow cooling, the mass is subject to moulding. The melted mass is moulded and, in order to prevent the product from breaking, it is necessary to gradually cool it down. The glass, completely cooled, is then subject to several refining operations.
Glass sheets without flaws can be used to produce mirrors. The reflecting surface can be obtained by applying a thin layer of white metal on the glass: the layer can be made of silver for precious mirrors, lead for dark mirrors, tin and aluminium for ordinary mirrors.

Special reports

  • 16 July 2013

    Van Allen belts

    ...and the spectacular phenomenon of polar auroras

    5 January 2005

    Tsunami in the Maldives

    On the 26th December 2004, an earthquake...

    8 November 2013

    Magnets and superconductors

    Which one of us has not played at attracting small pieces of iron with a magnet?

  • 10 January 2012

    Shale gas

    Unconventional gas: shale gas

    6 September 2009

    Oil fields beneath the ice

    Con la graduale scomparsa del ghiaccio marino in seguito al...

    13 May 2013

    Small steps, great footprints

    Have you ever wondered how much space is taken up by an apple or a steak?...

  • 15 September 2008

    Natural gas

    Natural gas has been the last fossil fuel to assert itself on a global scale...

    18 January 2016

    Ten years of oil demand

    Eni has recently published the 14th edition of the 2015 World Oil and Gas Review...

    30 April 2019

    Urban woods

    When walking along a tree-lined avenue in a crowded and traffic-congested city, wrapped up in our daily commitments, we do…

From the Multimedia section