Rocks

By Patrick

Igneous

Obsidian is an Igneous rock that is formed by lava cooling and hardening. Obsidian is a speshal Igneous rock, it has 70% or more SiO2 in it. It can be found in almost twenty countreys, including the United States and Canada.

Sedimentory

Chert is mainly found in the mountains of the United States, and even in Texas. Chert has silicon dioxide (SiO2) in it that other rocks dont have, in other words it has fossils in the rock.

Metamorphic

Slate is made up of quartz and illite pushed and melted together. Slate is found in almost 20 places around the world including the United States.

Rock Cycle

The rock Cycle is a cycle that shows how there are always the same number of rocks in the world. All the rocks are made in defferent ways. Sedimentory rocks are made when small rocks are pushed together to make one rock. Metamorphic rocks are rocks that under heat and presere make a rock. Igneous rocks are simpuly cooled lava.