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Notes on Rocks


What is a rock?

          It is a hard substance formed from one or more minerals.


What is a mineral?

It is a naturally occurring, inorganic solid that has a definite chemical composition and crystal structure.

Most minerals are made from the eight most abundant elements in Earth’s crust: Oxygen, Silicon, Aluminum, Iron, Calcium, Sodium, Potassium, and Magnesium.


What are the types of rocks and how are they categorized?

          There are three types of rocks: Igneous, Sedimentary and Metamorphic.  They are grouped into these categories by how the rocks form.



The Rock Cycle