From Simple English Wikipedia, the free encyclopedia
Sandstone
is a
sedimentary rock
. It is a rock made of compacted
sand
. Sand is small grains of
rocks
and
minerals
(such as
quartz
and
feldspar
). These are the most common
minerals
in the
Earth's crust
.
Sandstone which is resistant to
weathering
is used for building in many countries. It can be a hard rock. For example, paving slabs can be made out of hard sandstone.
Sandstone is converted into
quartzite
through heating and pressure. This happens when rocks are squeezed and heated under a
mountain
chain.
[1]
Sandstone is most likely to be deposited from fast pacing water such as rivers.
Sandstone forms in two stages. First, layers of sand build up as
sediment
, either from water or from air (as in a
desert
).
Then sand particles are compacted by pressure of overlying deposits, and cemented ('glued' together).
[2]
The 'cement' is either
calcite
(
calcium carbonate
),
quartz
(
silica
), or
clay
.
Iron oxide
often makes sandstone a reddish color.