Basalt is a dark, fine-grained volcanic rock that forms when lava cools quickly at the Earth's surface. It is primarily composed of minerals like plagioclase, pyroxene, and olivine, giving it a characteristic dark color. Basalt is commonly found in oceanic crust and volcanic islands, making it one of the most abundant types of rock on Earth. This rock plays a significant role in the geology of our planet. It is often used in construction and road building due to its durability. Additionally, basalt can be found in various forms, such as columnar basalt, which features unique, hexagonal shapes formed during cooling.