Granite

Granite is the most widespread of igneous rocks, underlying much of the continental crust.  Granite is an intrusive igneous rock. Intrusive rocks form from molten material (magma) that flows and solidifies underground, where magma cools slowly.  Eventually, the overlying rocks are removed, exposing the granite.   Granites usually have a coarse texture (individual minerals are visible without magnification), because the magma cools slowly underground, allowing larger crystal growth.

Granites are most easily characterized as light colored and coarse grained as a result of cooling slowly below the surface. Color variation is a response to the percent of each mineral found in the sample.  The crystals in granite provide a variety of mixed colors — feldspar (pink or red), mica (dark brown or black), quartz (clear pink, white, or black) and amphibole (black).

Granite is high in quartz (about 25%), feldspar, and mica. It is widely used for architectural facades, construction materials, ornamental stone and monuments. Over 40% of dimension stone quarried is granite.  Crushed granite is used as a durable construction material in asphalt and concrete used in highway and infrastructure projects.

Type

Rock

Description

Granite is the most widespread of igneous rocks, underlying much of the continental crust.  Granite is an intrusive igneous rock. Intrusive rocks form from molten material (magma) that flows and solidifies underground, where magma cools slowly.  Eventually, the overlying rocks are removed, exposing the granite.   Granites usually have a coarse texture (individual minerals are visible without magnification), because the magma cools slowly underground, allowing larger crystal growth.

Granites are most easily characterized as light colored and coarse grained as a result of cooling slowly below the surface. Color variation is a response to the percent of each mineral found in the sample.  The crystals in granite provide a variety of mixed colors — feldspar (pink or red), mica (dark brown or black), quartz (clear pink, white, or black) and amphibole (black).

Granite is high in quartz (about 25%), feldspar, and mica. It is widely used for architectural facades, construction materials, ornamental stone and monuments. Over 40% of dimension stone quarried is granite.  Crushed granite is used as a durable construction material in asphalt and concrete used in highway and infrastructure projects.

Relation to Mining

Granite is mined as either crushed stone or dimension stone mainly using open pit mining methods. Crushed granite represents 16% of the total crushed stone produced in the U.S., and it is the second-most utilized crushed stone in the U.S. Crushed limestone is by far the most commonly used crushed rock in the U.S., representing 70% of total crushed rock consumption. Crushed granite is used in road construction and railroad beds. Larger pieces of granite are used to stabilize the land around roadways to minimize and even eliminate soil erosion.

Please see either for information about granite mining.

Uses

There is an enormous abundance of granite throughout the United States, so it is not a surprise that a significant amount of granite is used in crushed stone applications. Crushed granite represents 16% of the total crushed stone produced in the U.S., and it is the second-most utilized crushed stone in the U.S. Crushed limestone is by far the most commonly used crushed rock in the U.S., representing 70% of total crushed rock consumption. The 16% represented by crushed granite (265,000 tons per year) is used in road construction and railroad beds. Larger pieces of granite are used to stabilize the land around roadways to minimize and even eliminate soil erosion.

Granite is used extensively as dimension stone. It is used in the construction of buildings, both as building blocks and as veneers on frame structures. Because it can be smoothed to a very high polish, granite has found extensive use in memorials, headstones, monuments, carved decorations on buildings, statues and the like. Approximately 1.5 million tons of dimension stone is produced annually in the United States. Of this, granite accounts for over 400,000 tons (27%), second only to limestone.