An igneous rock of volcanic origin, usually containing 10 to 50 percent quartz, at least 50 percent feldspar and some silicia. Most granites are resistant to abrasion, weathering and chemicals. Feldspar gives them their color. Volcanic flow that cools slowly has bigger crystals while flows that cool rapidly have very small crystals.
A sedimentary rock composed of fine grains of quartz sand (0.6mm to 2mm diameter) bonded by a cementing material, commonly silica, iron oxide or calcium carbonate. Quartzite is usually very dense, hard to scratch and abrasion resistant. If often features veins and complex color patterns similar in appearance to marble.
A metamorphic rock composed predominately of magnesium silicate. Typically green in color. Serpentines are thought to be formed very deep undersea by magma emerging through cracks in the ocean floor at temperatures up to around 500 degrees Celsius. Serpentines are very dense, abrasion and chemical resistant though they are typically classified as softer granites.
Soapstone is a serpentine containing talc white makes it feel like a bar of soap. The talc also makes it easy to scratch, a characteristic preferred in rustic décor. Often used as countertops in chemistry labs, where it’s resistance to acids is important, and on fireplaces where it’s unique heat retention characteristic is valued.
A sedimentary rock consisting chiefly of the mineral calcite. Often contains fossils or shell formations, formed as bones and shells of fish accumulated on the sea floor. Ancient sea beds have become hills and mountains, allowing quarrying. Often very dense and durable, limestone has been used for paving, counters and wall cladding on exterior and interior surfaces for thousands of years.
A metamorphic rock consisting of coarse grained re-crystallized calcite. Most marbles were originally limestones that underwent tremendous pressure and heat, causing the limestone to meal then re-crystalize. In most cases the resulting stone, marble, is more dense and durable than limestone.
A sedimentary rock, travertine is a type of limestone that formed by evaporation of hot water containing dissolved calcium, thus leaving finely crystalized calcite deposits. These deposits accumulate in horizontal layers over thousands of years. The holes in travertine are the pathways for the water as it passed up from the geothermal springs below. Its natural color is white. The other colors come from chemicals in the water and other debris, including ash from fires and volcanoes, animal remains and vegetation. Travertine is very durable, often used for exterior wall cladding and paving installations around the world.
A compact sedimentary rock is a type of limestone that formed by evaporation of cold water containing dissolved calcium, leaving a translucent variety of calcile, often in the form of stalagmite and stalactites inside caves. Its natural color is translucent white. The other colors usually come from miute concentrations of chemicals carried by water dripping into the cave. Onyx is extremely dense but lacking in bending strength. It is often used for interior counters, wall claddings and flooring.