Stone

Building structures from stone is the foundation of masonry. Stone has been used in structures for thousands of years. Although modern materials have become a dominant choice in the building and construction industry, stone still has a place for it's qualities of durability, beauty, and representation as an iconic material.

In geology, the materials from which building stones are obtained are genrally termed rocks. Rocks can come in three naturally different forms:

• Igneous rocks comes from the cooling of magma, either at the earth's surface following a volcanic eruption or within earth's crust. Igneous rocks are often hard and non-porous.
• Sedimentary rocks are often relatively soft compared to other types of rocks. Most come from sediments produced by erosion, which settled into layers, were compacted and lithified over time. An example of this kind of rocks is sandstone. Limestones instead formed by the precipitation of carbonates from seawater.
• Metamorphic rocks are also often hard and non-porous but come from rocks that ware changed by pressure or heat at the contact with bodies of magma or deep in the crust. Marble is a distinct example of metamorphic rock, derived from the metamorphism of a limestone; in marbles, you can often see veins and folded dark horizons that formed during the plastic deformation of the parent limestone.

These different types of stone lend themselves to different applications. For example, because sedimentary rock is softer than igneous or metamorphic stone, it would not be the best choice for a retaining wall, or in applications that involve running water.

Much of the stone used in construction comes from quarries, that exist as a part of mining for some other mineral, or are a source of a particular stone to begin with. The stone pulled from these chasms in the earth's crust is very "raw", and may be sent to a masonry to be refined or shaped, especially in the case with marble.