| Granite is igneous rock. It is light in | | | | Where Granite is Found |
| color, but the grain can be medium or | | | | Granite is found on every continent of |
| coarse. The rock is composed mainly of | | | | the earth, especially in places where |
| alkali feldspar and quartz and is easily | | | | the earth has been worn away by erosion. |
| recognizable by the visible grains of | | | | It often forms the core of mountains |
| the various dark minerals. Granite rocks | | | | that forceful pressures within the earth |
| are the most common of all crystalline | | | | have pushed upward. Sometimes bodies of |
| rocks found on the surface of the earth. | | | | granite are found in large outcroppings |
| They are found all over the world, | | | | of rocks that are found in chimney like |
| usually in great masses called | | | | and overhanging rock formations. The |
| batholiths that often extend over | | | | Appalachian Mountain range in the United |
| thousands of miles. This is a popular | | | | States is composed mostly of granite. It |
| material form use in monuments and | | | | is also found in the Ozark Mountains, |
| buildings because of its hardness, | | | | the Black Hills, and the front range of |
| durability and the range of colors. | | | | the Rocky Mountains. Granite is also |
| Composition of Granite | | | | produced in many states such as Georgia, |
| Granite is composed mainly of potash, | | | | California, Virginia, Minnesota, South |
| feldspar and quartz. The color of the | | | | Dakota and the Carolinas. |
| rock varies from gray to red and is | | | | How Granite is Formed |
| usually determined by the amount of the | | | | Geologists have two different theories |
| potash feldspar. If there is a lot of | | | | about how granite was formed. One theory |
| glassy crystals in granite, it will tend | | | | says that granite formed directly from |
| to have a bluish color. Dark minerals, | | | | molten lava. The other theory states |
| such as hornblende, biotite mica and | | | | that it was formed as a result of the |
| muscovite mica can sometimes be found in | | | | alterations of other rocks and that |
| granite. Some types of rock that are | | | | granite is metamorphic rock, rather than |
| commonly called granite contain | | | | igneous rock. |
| different amounts of plagioclase | | | | Uses of Granite |
| feldspar. Rocks that contain about | | | | Granite has been used a building |
| one-fifth of the amount of potash | | | | material for thousands of years. In |
| feldspar relative to the amount of | | | | ancient Egypt, the obelisks were built |
| plagioclase feldspar is really | | | | from granite. Today, granite is used in |
| granodiorite, rather than granite. Rocks | | | | building monuments, curbs for roads, |
| that have the same composition as | | | | tombstones, and as a structural element |
| granite, but have a very large amount of | | | | in buildings. |
| crystals are known as pegmatite. | | | | |