Group
Rock
Igneous
Granite
Uses
Where found
Dun Laoghaire Pier
Wicklow Mts.
Kaolin Clay for high
class
Pottery.
Basalt
Sedimentary
Limestone
Sandstone
Metamorphic Marble
Quartzite
A road metal.
Cement
Polished for headstones
and statues
Ground to a powder to
improve the PH of a
soil.
Public buildings
e.g. the National
Museum
Road metal.
Antrim Plateau.
Burren Co.
Clare.
Cork and Kerry
Mts.
Ornamental stone for
fireplaces, statues and
altars.
Connemara
Kilkenny.
A road metal.
Sugar Loaf
Co. Wicklow.
How it was formed
Hot molten magma cooled slowly beneath the earth’s crust.
This produced large crystals.
Granite is made up of quartz(sand) grains; mica(shiny
pieces) and feldspar which acts as a cement for the other 2
elements.
Lava cooled quickly on the earth’s surface. This produced
small crystals. It is black in colour and contains iron which
can rust.
Limestone is formed under a shallow sea. It is made up of
millions of shells of sea creatures that are crushed together
by the weight of other deposits and by the weight of the
water. It is formed in layers.
Sandstone was formed in a shallow sea. It is made up of
grains of sand deposited by rivers in the shallow sea and
compressed into solid rock by the weight of the sediments
and the weight of the water. It is red in colour due to the
presence of iron.
Limestone is changed by heat or pressure into marble. It can
have a variety of colours ranging from pure white to black or
green.
Sandstone is changed by heat or pressure into quartzite. This
is a very hard resistant rock.