1. Sedimentary rocks: These rocks are formed from the accumulation and cementation of sediments, such as sand, mud, and shells. These sediments can come from the weathering and erosion of other rocks, the remains of organisms, or chemical precipitation. Some examples of sedimentary rocks include sandstone, limestone, and shale.

2. Extrusive igneous rocks: These rocks are formed when magma (molten rock) erupts onto the Earth's surface as lava and cools quickly. The rapid cooling process results in smaller crystals, giving these rocks a fine-grained texture. Examples of extrusive igneous rocks include basalt, rhyolite, and obsidian.