Question

What are some common uses of igneous rocks?

Answer 1

Hint: Rocks usually contain a variety of minerals, some of which are important and others that are merely decorative. Each rock type formed under unique conditions, resulting in a reasonably predictable group of minerals.

Complete answer:
According to their sources, rocks are classified into three categories: Metamorphic - Igneous – Sedimentary. There are a number of igneous rocks that are found on Earth. Granite is the most common igneous rock found on the earth surface other igneous rocks are pumice, gabbro, basalt, and obsidian
Granite – It is a plutonic igneous rock. It is medium to coarse-grained and contains a lot of silica, potassium, sodium, and quartz, but not a lot of iron, calcium, or magnesium. Buildings, temples, and ornamental stone are the most common uses for granite.
Pumice – It is a porous, brittle type of rhyolite that is light enough to float and is an igneous-volcanic rock. It is produced when granite-rich magma erupts at the surface of the earth or intrudes the crust at deeper depths. It's found in hand soaps, emery boards, and other abrasive materials.
Gabbro - A massive igneous-plutonic rock that may have a layered structure formed by successive layers of varying mineral composition. Crushed stone is commonly used in asphalt aggregate, road metal, train ballast, and other applications. Dimension stone is cut and polished in smaller amounts (called black granite).
Basalt - It is a dark grey to black igneous volcanic rock that is the volcanic counterpart of plutonic gabbro and is rich in ferromagnesian minerals. Basalt can be mixed with other materials to make aggregates.

Note:
i) One of the three major rock groups is igneous rock, also known as magmatic rock. The other two are sedimentary and metamorphic rock. Igneous rock is formed as magma or lava cools and solidifies.
ii) Magma can be generated by partial melting of existing rocks in the mantle or crust of an earth. One or more of three processes may cause melting: a rise in temperature, a decrease in pressure, or a change in composition.