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            Rock and minerals
          
        
        
          
            Mineral mixtures
          
        
        
          Granite rock is
        
        
          made up of different
        
        
          coloured minerals. The
        
        
          black mineral is mica,
        
        
          the pink is feldspar,
        
        
          and the grey mineral
        
        
          is quartz.
        
        
          
            Feldspar
          
        
        
          is used for
        
        
          glazing
        
        
          ceramics.
        
        
          
            Mica
          
        
        
          is
        
        
          ground up
        
        
          and used
        
        
          in paint.
        
        
          
            Quartz
          
        
        
          can also
        
        
          occur as the
        
        
          gemstone
        
        
          amethyst.
        
        
          
            Crystals
          
        
        
          Minerals usually form crystals.
        
        
          Crystals have a number of flat
        
        
          surfaces. The largest crystals
        
        
          form when minerals in magma or
        
        
          trapped liquids cool very slowly.
        
        
          
            Halite
          
        
        
          Salt is the mineral
        
        
          halite. We add it to our
        
        
          food for flavour.
        
        
          
            Quartz
          
        
        
          from sand is used
        
        
          to make the silicon chips in
        
        
          calculators and computers.
        
        
          
            Kaolinite
          
        
        
          is used to make
        
        
          crockery. It is also used to
        
        
          make paper look glossy.
        
        
          
            Illite
          
        
        
          is a clay mineral
        
        
          and is used in terracotta
        
        
          pots and bricks.
        
        
          
            Mica
          
        
        
          is used to make
        
        
          glittery paint and
        
        
          nail polish.
        
        
          
            Graphite
          
        
        
          is the “lead”
        
        
          in pencils. It is also
        
        
          used in bicycle brakes.
        
        
          Pumice is filled with air bubbles, so some pieces can float.
        
        
          
            What is a mineral?
          
        
        
          A mineral is a solid that occurs naturally.
        
        
          It is made up of chemicals and has a crystal
        
        
          structure. Minerals are everywhere you look.
        
        
          We use minerals to build cars and computers,
        
        
          fertilize soil, and to clean our teeth.
        
        
          
            Rock salt
          
        
        
          is a mineral that is
        
        
          spread on roads in icy weather.
        
        
          It makes the ice melt.
        
        
          
            Rhodochrosite
          
        
        
          is a rose-coloured
        
        
          gemstone used
        
        
          in jewellery.
        
        
          
            Quartz
          
        
        
          
            stalactites
          
        
        
          form in caves
        
        
          over thousands
        
        
          of years.
        
        
          
            Minerals in your
          
        
        
          
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