Sandstone is a building material commonly used from earliest times throughout Britain – and no doubt everywhere else in the world the rock occurs! Sandstone, as the name tells us is made from sand, but made from very ancient sand, millions and millions of years ago; it’s a sedimentary rock, a rock formed by the laying down of sediment in ancient times. It’s a hard sedimentary rock formed by the weathering, erosion and accumulation of particles of tiny fragments, sand-sized fragments of other rocks such as igneous, metamorphic or even other sedimentary rocks. Sand deposits would gather in places that if you think about it you would expect, desert dunes, coastal beaches – which we know well living very near a sandy coastal beach and having deposits of sand blowing into our house all the time! It can also gather on the bottom of seas, rivers, and streams – and this is the most common illustration we see in school geology lessons! As millions upon millions of years pass, the sand grains, whether in a dune or a sea bed, becomes compacted and pressed together to form the rocks we know today. Here is a good word, diagenesis, the process which takes place over millions of years to form these rocks.
here is a wonderful and most informative apge about sandstone, its geological and geographical history, its architectural history and use, and its heritage in Britain today.