Igneous Rocks

What is an igneous rock? according to the book Rocks and minerals (Zim 110) an igneous rock is a rock made of magma cooling an harding. But is there more to igneous rocks? Are there types of igneous rocks? Where and how are igneous rocks formed and does where they form affect them? What are some types of igneous rocks? All of these questions will be answered on this web page.

Our first question, are there  more types of igneous rocks? Yes, there are two. According to Rocks and minerals (Zim 111 and116) they are intrusive and extrusive. Intrusive igneous rocks are formed below the surface but ones formed near the surface usually become extrusive. The process to becoming intrusive is gradual one which many liquids and gazes stay longer. The other type of igneous rocks are extrusive rocks. They come out as lava from a volcano and then cools.

Our next question,where and how are igneous rocks formed? As it says in rocks and minerals (Zim 110) all igneous rocks are made from lava cooling and harding but where they do that is what the difference is. If the rock cools and hardens near or at the surface it becomes extrusive. If the rock cools or hardens below the surface it becomes intrusive.

Our final question, what are some igneous rocks? As it says in the book Rocks and Minerals (Zim 112and 116-117) you can classify them through the two types we already know, intrusive and extrusive. Some intrusive rocks are granite, pegmatite, syenite, Diorite and gabbro. Some extrusive rocks are rhyolite, obsidian, andesiteand basalt. If you are wondering what the ending ite means it means mineral or rock.

As you can see there is a lot more to rocks then meets the eye. There are different types, they are made different and there are different types . If you still think that there just one rock I don't think that you read this page.

according to the ap archives in the hudson middle school                                                                                        by: Samir