JUNIOR GEOLOGIST Discovering Rocks Minerals and Gems CNEOUS ELISA PETERS Eat Britannica Educational Publishing IN ASSOCIATION WITH ESPN A ROSEN EDUCATIONAL SERVICES
MADE FROM MAGMA Did you know that there is more than one kind of rock Igneous rock is one of the three kinds of rock found on Earth The other two are sedimentary rock and metamorphic rock Each of these kinds of rock forms differently Igneous rock is formed from a soft fluid substance called magma Magma is often described as molten or When a volcano erupts you can see melted rock pouring out of it 4
melted rock Igneous rock forms when magma cools down and hardens There are many types of igneous rock Granite is one of the most common forms This hard rock is used in building It is also popular for kitchen countertops Obsidian is an igneous rock too Obsidian is a shiny jet-black rock It was once used to make mirrors When a solid is heated it melts and becomes liquid It is called molten when very high heat causes the melting Vocabulary Obsidian can form sharp edges when it breaks It was once used to make knives 5
