Types of rocks:
Sedimentary rock** formed from partials of sand, shells, pebbles, and other fragments of material. Together, all these particles are called sediments.
Igneous rock** formed from compacting and cementation
Metamorphic rock** formed from extreme heat and/or pressure
Examples:
Sedimentary- Sandstone
Igneous- Obsidian and Basalt
Metamorphic- Gneiss and Slate