ShareRocks & Minerals - Rocks and Minerals
What is a rock?
At first this seems like an easy question. We see rocks every day. But
have you ever thought about them (besides when you stub your toe?) Each
rock is like reading a story. By studying them we can learn about how
the crust of Earth is formed.
A rock is a mixture of one or more minerals and sometimes organic matter (something that was once living). Some rocks are shiny, some are flat and dull, and others are very compact. Analyzing these differences can help us understand how they were formed.
So a rock is a mixture or combination of minerals.
Reminder! Rocks are made of one or more minerals. Keep reading to learn more!
The mineral quartz can break down into grains of sand. These grains are then cemented to form a new kind of rock. Do you know what that rock type is? (Drag your mouse over the photograph to see an example of something it changes into.) |
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| Hematite already inside the earth comes out of Earth in a lava flow. As the lava cools, it becomes solid and you can now find the mineral hematite in the rock. (Drag your mouse over the photograph to see an example of basalt.) |  |
| Calcite is found in many things such as seashells, bones and the rock. It changes into marble. (Drag your mouse over the photograph to see an example of marble.) |  |
| These three minerals, quartz, hematite, and calcite are also found inside Earth. As the magma slowly cools in the earth these minerals form crystals to make a rock called granite.(Drag your mouse over the photograph to review how granite is formed.) |  |
