To choose the right stone for you, it helps to have some working knowledge of its origins, how it was wrought from the earth, and its processing into the finished product. Typically, a general overview of your product curtails future problems with your project.
In Modern Times
The demand for natural architectural stone has increased so radically within the last twenty years that quarrying has become a major industry for many countries around the world. Whereas previously some of these countries sent raw blocks to Italy for fabrication into marketable precut units, most now have installed machinery to handle their own lines of production.
Brazil, for example, is now one of the world's largest suppliers of granite, exporting both slab and precut tile material prepared in local manufacturing plants. Despite this, Italy still presides as the largest exporter of stone, and is arguably the most prodigious supplier of stone technology.
Stone has been the medium of choice for the edification of man from time immemorial; indeed, many ancient cultures immortalized their gods with stone temples and tombs. In fact, archaeological evidence exemplifies the structural durability and beauty of stone. Marbles used by the Emperor Hadrian to construct his enormous villa near Rome, and those used in the Parthenon in Athens are still quarried to this day. Yet in those bygone days stone masons did not have the advantage of the specialized quarrying and cutting machinery we have today.
Removing blocks from quarries was a laborious process; the task of cutting stone into usable proportions and then installing the stone was just as taxing. A plethora of evidence exists regarding how ancient craftsmen erected megalithic stone structures, which set a path for modern advancements in architecture.
Stone Processing Today
Most architectural stone today is quarried from mountainsides or hillsides, open pit mines, or from "galleries" - great caverns within the heart of mountains. The methods used are typically the same for each quarrying condition. The object is to ascertain the best material (judged in purity and fracture) and to remove it in blocks large enough to yield slabs of a functional size for commercial use, or for cut-to-size tile lines. The demand for the latter differs from market to market, but the North American consumer requires predominantly square units in 12, 16, 18, or 24 inch material. Typically they are 20mm (3/4 inch) in thickness, and 4-7ft tall by 8-11ft in length.
Types of Stone
Granite is a light-colored igneous rock that has large enough grains to be visible with the naked eye. This rock forms from the slow crystallization of magma below Earth's surface. Granite is composed of mainly quartz and feldspar with small amounts of mica, amphiboles, and other minerals. This composition of minerals usually gives granite a red, pink, gray, or white color with dark mineral grains visible throughout the rock. Granite is best used for countertops, floor tiles, paving stone, curbing, stair treads, building veneer, and cemetery monuments. Granite is hard enough to resist most abrasion, strong enough to bear significant weight, inert enough to resist weathering, and it accepts a brilliant polish. These characteristics make granite a very desirable and useful dimension stone.
Marble is a metamorphic rock that forms when limestone is subjected to heat and pressure of metamorphism. It is composed primarily of the mineral calcite and usually contains other minerals, such as mica, quartz, pyrite, iron oxides. When acidic elements come in contact with calcium carbonate, it creates an etch. An etch is not a scratch. Rather, it is merely the removal of polished finish on the surface. Marble can come in a polished or honed finish. It is softer than granite, so the best application for it is on fireplace surrounds, bathroom, some furniture, and in generally less-traveled areas. Marble is rated as a three on the Mohs Hardness Scale.
Quartzite is a nonfoliated metamorphic rock composed almost entirely of quartz. It forms when a quartz-rich sandstone is altered by heat, pressure, and chemical activity of metamorphism. These conditions recrystallize the sand grains and the silica cement that binds them together. The result is a network of interlocking quartz grains of incredible strength. Quartzite, with a Mohs hardness of seven along with greater toughness, is superior to both granite and marble in many uses. It stands up better to abrasion in stair treads, floor tiles, and countertops. It is more resistant to most chemicals and environmental conditions. It is available in a range of neutral colors that many people prefer.
Care & Maintenance
Three mayor finish are in natural stones: polished, honed and leather.
Granite and natural quartzite you can use as a cutting board, it would not scratch.
Natural stone does not be damaged by heat, you can place any hot pans directly onto the surface.
For routine cleaning, use a damp cloth or paper towel and if necessary, a small amount of soap.