1. Granite: A hard, igneous rock that is often light-colored and speckled with crystals. It's commonly found in mountains and is used in construction.

2. Basalt: A dark-colored, volcanic rock that is very common on the ocean floor. It's also found on land, often in the form of lava flows.

3. Limestone: A sedimentary rock formed from the accumulation of marine organism shells. It's often light-colored and is used in construction and as a source of calcium.