What are the different types of rocks used in construction and how are they formed?

Rocks are natural materials that have been used for construction purposes for thousands of years. There are three main types of rocks that are commonly used in construction: igneous, sedimentary, and metamorphic rocks.

Igneous rocks are formed from solidified lava or magma. When hot magma cools and solidifies, it forms igneous rocks. These rocks are hard and durable and are commonly used in the construction of roads, bridges, and buildings. Granite, basalt, and pumice are examples of igneous rocks.

Sedimentary rocks are formed from the accumulation and cementation of small particles such as sand, mud, and gravel. These rocks are relatively soft and can be easily carved and cut. Limestone, sandstone, and shale are examples of sedimentary rocks that are commonly used in construction.

Metamorphic rocks are formed from the transformation of existing rocks due to high pressure and temperature. Marble, slate, and gneiss are examples of metamorphic rocks that are commonly used in construction.

The choice of rock type for construction depends on various factors such as strength, durability, cost, and aesthetic appeal.