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Posted by on Nov 12, 2018 in TellMeWhy |

What Is Granite?

What Is Granite?

What Is Granite? Granite is a very hard kind of rock made up of small pieces of mica, quartz and felspar and sometimes other rocks as well. There are many kinds of granite and they may be pink, grey or white. But the most striking thing about it is that the pieces of rock from which it is made are all crystalline and shine like a wall of snowflakes.

It has a felsic composition and is more common in continental crust than in oceanic crust. They are crystallized from felsic melts which are less dense than mafic rocks and thus tend to ascend toward the surface. In contrast, mafic rocks, either basalts or gabbros, once metamorphosed at eclogite facies, tend to sink into the mantle beneath the Moho.

construction stone

It is nearly always massive (i.e., lacking any internal structures), hard, and tough. These properties have made it a widespread construction stone throughout human history. One city in Scotland, called Aberdeen, is known as the silver city, because of the way the granite from which it is built shines in the sun. This rock is widely used for building, and is especially useful for large engineering jobs such as the making of breakwaters. Not only does it stand up well to the weather but, unlike many other rocks, it can be quarried in huge slabs. It is also used as an ornamental stone after being polished to a smooth surface.

Granite is one of the rocks most prized by climbers, for its steepness, soundness, crack systems, and friction. Well-known venues for granite climbing include the Yosemite Valley, the Bugaboos, the Mont Blanc massif (and peaks such as the Aiguille du Dru, the Mourne Mountains, the Adamello-Presanella Alps, the Aiguille du Midi and the Grandes Jorasses), the Bregaglia, Corsica, parts of the Karakoram (especially the Trango Towers), the Fitzroy Massif, Patagonia, Baffin Island, Ogawayama, the Cornish coast, the Cairngorms, Sugarloaf Mountain in Rio de Janeiro, Brazil, and the Stawamus Chief, British Columbia, Canada.

Granite rock climbing is so popular that many of the artificial rock climbing walls found in gyms and theme parks are made to look and feel like granite. It is found all over the world and forms part of most of the world’s mountain ranges. There is a city in the State of Illinois called Granite City, while the Mountain State of New Hampshire on the eastern side of the United States is sometimes called the Granite State on account of the granite quarries there. You may have heard the expression “granite features” used to describe persons. This means that they have cold, hard faces, like a granite rock.

Content for this question contributed by Kristina Cady, resident of Ware, Hampshire County, Massachusetts, USA