Soft as granite

The main minerals present in a true granite are quartz, feldspar and mica along with dark ferromagnesian minerals. The term granite within the trade is often applied to any igneous rock with a large crystalline structure. Easily shaped, softer areas in true granites are often exploited in the search for building materials. Meanwhile, the decomposition of large areas of granite is a relatively slow process but certain minerals are quite unstable when exposed to the elements. These pockets of decay are often close to the surface of the granite regions and were the first to be exploited for building materials. Traditional methods of shaping granite for building include the use of ice where water is deliberately poured into a series of prepared holes. Another is by dry wooden pegs and metal feathers and wedges which uses wrought iron wedges driven between metal feathers that direct the force from hammer blows.