Marble is used commonly used as a building material and most noticeably, for sculpture. The stone is a non-foliated metamorphic rock composed of recrystallized carbonate materials. Most non-foliated rocks are produced by contact metamorphism; which is when heat from cooling magma modifies the structure of rock previously crystallized, resulting in its foliation becoming slightly visible.
Granite is commonly used as construction stone because it is a distinctly tough stone. Granite is a type of igneous rock with at least 20% quartz by volume, which is visibly crystalline in texture and formation. It is composed of feldspar, which gives granite that gray or flesh-color (pink-red) façade. Granite also crystallizes from magma that slowly cools, deep beneath the earth’s surface. Interestingly, granite is one of the stones that serves as the foundation of our world’s continents as we know them.
Travertine is a sedimentary rock and form of limestone formed by a rapid precipitation of calcium carbonate at the mouth of a limestone cave or hot spring. The porous nature of travertine is distinct as algae, bacteria, and other organisms colonize and absorb it. Italy has the most well-known travertine quarries in the world, which has includes historic value such as the famous St. Peter’s Basilica, built by Michelangelo who made travertine his choice stone. Travertine is commonly used as a building material such as paving pathways and patios. There are natural holes in the stone, which is sometimes filled with grout, or sometimes left open depending on the preference of the customer. Since the stone is on the softer side of the spectrum, travertine can prove difficult to finish and maintain.
Limestone is a sedimentary rock composed mainly of naturally occurring calcium carbonate minerals. The rock is composed mostly of grains that come from skeletal fragments (shells) of marine organisms. Limestone is most commonly used in architecture as it is long-lasting and holds up to exposure of harsh conditions quite well. It’s no surprise that the Great Pyramid in Egypt in addition to other complexes, were cut from Limestone. It is readily available easy to cut or carve, and is a solid material to use as the base of highly trafficked places like roads.
Slate is a homogenous metamorphic rock and that is largely composed of quartz and muscovite, formed from clay on ancient sea beds. It can be defined as a fine-grained rock derived from clay and shale that can be split into thin sheets. The most common uses for slate include roofing and flooring tile as slate can form smooth, flat sheets of stone. It has been used to for fireproofing structures and for building electric switchboards since it is a great electrical insulator. Depending where the slate is extracted, its colors can range from the most common gray, to greens and purples. If you happen to see a fossil in any of your tiles, you can accent the room so it can be seen easily.
Sandstone is a sedimentary rock that is formed from cemented grains of sand. The cementing material in sandstone can be made harder or softer depending upon the make-up of the cementing material, which adds flexibility to its use (i.e. adding more quartz makes sandstone harder). Sandstones mostly come in a range of earth tones such as red, brown, and green, but have been known to deviate in color. Sandstone is widely used in the construction industry due to its durability and sheer strength. It’s commonly mixed in building and paving materials., Ironically, sandstone can also be crushed back into its fundamental state, back to sand, for other building and design-related projects. Sandstone is usually found in deserts like the vast Sahara Desert, old rivers, lakes, beach shores, Deltas, and similar dry environments where there was once a sea or body of water.
Quartzite is a form of sandstone that has gone through metamorphosis by heat and pressure, therefore making it a hard and non-foliated. Since it so rigid and sharp, it is very resistant to chemical weathering and serves as a great building material for railroad track ballasts and other road construction. It is also used decoratively to cover walls, as flooring, and for roofing tiles. Pure quartzite is typically gray or white, although shades of red, orange, and pink have been found due to elevated amounts of iron oxide and/or other impure minerals.