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The Properties of Natural Granite

view:author:Magic Stoneupdate:2012/12/18

Granite has a noticeably granular, crystalline structure. The term derives from the Italian word granito, or small grain. The grains can be consistent in size or they could vary. They could range from the size of a BB (2mm) to the size of a quarter (25mm). Granite is comprised of feldspar and quartz. It can also contain micas and hornblende.

Granite was formed from molten materials. Its source is magma, which is still escaping from the core of the earth in the form of lava. What makes this mixture of feldspar, quartz and silica different from lava is that it has cooled very slowly, under extreme pressure, deep within the earth.
The more slowly the magna has cooled, the finer the resulting crystal structure or grain. This cooling process, which has taken millions of years, has produced a stone which is extremely dense and hard. In fact, it is second only to diamonds in hardness.
This igneous stone is very consistent in appearance. Each square foot looks almost like the next. There are generally no veins present. There are some types, Juparana is an example, which seems to show a band of dark color which can look like a vein. Upon closer examination, this vein will be seen to be granular in nature. It will be much wider than a quartz or oxide vein found in marble.
Granites which were allowed to cool slowly, without interruption, are very consistent. But if earthquakes, continental plate movement or glacial activity have disrupted these formations, they were moved around and reheated. Impurities fell into tiny fissures and produced a wavy or veiny look.
Granites are quarried in many countries around the world. Magic Stone have deposits of granite in the U.S. It can also be found in Canada, South America, Scandinavia, Italy, India and China.
Granite can be finished in several ways. The surface can be highly polished; this means it will reflect a great deal of light. It can be honed to exhibit little if any light reflection, and to be more slip-resistant. Or it can be given a flamed or thermal finish, which is achieved by running gas jets (flame) over the surface of the stone. The very high temperatures produced by the burning gas (3,100-3,600 degree F) cause a rapid evaporation of moisture from within the stone, causing crystals at the surface to explode. The resulting surface is heavily textured. A flamed or thermal finished surface will offer the best traction for walking. It is very slip-resistant and is often found in commercial lobbies or on exterior walkways.
Granite is very dense and hard. It stands up well to heavy foot traffic, which makes it the stone of choice for commercial lobbies and walkways. It is resistant to most chemicals, although oils can permeate into it. Granite is ideal for counter and bar tops. Some of the very light grey to white granites are somewhat more porous than most other types. White granite will contain tiny flecks of iron; these can pose a problem with rusting when used on exteriors or in wet areas.