Mudstone, shale, and limestone are examples of sedimentary rock likely to contain fossils. As the layers of sediment build up on top of one another, they create a physical timeline. The oldest layers, ...

The Eye is made up of a mixture of sedimentary and igneous rock, and erosion across the surface shows fine-grained rhyolite ...

These rocks are formed when magma solidifies. As the magma cools, mineral crystals will begin to grow. These crystals will grow and interlock to form a hard crystalline rock. Basalt is usually ...

Experts distinguish minerals based on their crystal structure ... meaning they only contain one mineral. Limestone, for example, is a sedimentary rock made exclusively of the mineral calcite ...