TYPES AND USES OF STONE
Mineral – contains quartz, feldspars and silic. Mineral stones were originally produced by volcanic activity. Includes granite, quartzite, serpentine and soapstone.
GRANITE: Granite- an igneous rock of volcanic origin, usually containing 10 to 50 percent quartz, at least 50 percent feldspar and some silica. Most granites are resistant to abrasion, weathering and chemicals. Feldspar give them their color. Volcanic flows that cooled slowly have bigger crystals flows that cooled rapidly have very smaller crystals.
QUARTZITE: Quartzite- 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. It often features veins and complex color patterns similar in appearance to marble.
SERPENTINE: Serpentine- a metamorphic rock composed predominantly 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 Celcius. Serpentines are very dense, abrasion and chemical resistant though they are classified as softer granites.
SOAPSTONE: Soapstone is a serpentine containing talc which makes it feel like a bar of soap/ The talk also makes it easy to strach, a characteristic preferred in rustic décor. Often used as countertops in chemistry labs, where its resistance to acids is important, and on fireplaces where its unique heat-retention characteristic is valued.
Organic – contains calcium, typically from the shells and bones of fish. Limestone is the mother stone of marble, travertine and onyx.
LIMESTONE: Limestone – a sedimentary rock consisting chiefly of the mineral calcite (CaCO3). Often contains fossils or shell formations, formed as bones and shells of fish accumulated on the sea floor. Ancient seabeds 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.
MARBLE: Marble- 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 melt then recrystallize. In most cases the resulting stone, marble, is more dense than limestone.
TRAVERTINE: Travertine- a sedimentary rock, travertine is a type of limestone that formed by evaporation of hot water containing dissolved calcium, thus leaving finely crystallized 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.
ONYX: Onyx- a compact sedimentary rock is a type of limestone that formed by evaporation of cold water containing dissolved calcium, leaving a translucent variety of calcite, often in the form of stalagmites and stalactites inside caves. Its natural color is translucent white. The other colors usually come from minute 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.