Rocks and Minerals

What is a rock? A rock is a hard, solid substance that forms parts of the Earth’s crust or top layer.

Rocks can be broken down into smaller pieces. Rocks are made up of dirt, minerals, and sand. Minerals cannot be broken down. However, some minerals are so small, they look like dust. When you add them to water, and the water evaporates (disappears), so does the mineral!

What is a mineral? A mineral is solid substance that is not living (inorganic), has a chemical composition (it had to have a chemical process such as heat to form), and a crystalline form (it is shiny, and looks like a crystal).

What chemical process do minerals go through? Minerals are chemically changed by the heat and pressure inside the Earth. The Earth is made up of layers, and the deeper you go into the Earth, the hotter it is, and the more pressure.

If a mineral has to look like a crystal, what is a crystal? A crystal is a solid shape that has specific patterns. There are 7 basic crystal patterns.

Where are minerals found? In rocks!

Wow, I really like learning about the Earth! If I want to study the Earth what would I be studying? Geology The people that study the Earth, and its materials are called geologists.

Geologists use many tools to dig, and investigate rocks, and minerals. Picks Measuring Tape Brushes Hand Lens

What do they measure? Geologists measure how big around a rock is, or the distance around a circular object. That is called the circumference of the rock.

What do they measure? Geologists measure how wide a rock is, or the distance across a circular object. That is called the diameter of the rock.

What do they measure? Geologists measure how thick a rock is from top to bottom. That is called the depth of the rock. You might think of this one, as you think of the thickness of a book.

How do geologists know what kind of rock, or mineral they have found? They measure the rocks, and put them into groups by their properties. Properties are things you can see, or observe. Examples are the size, color, shape, and texture.

Next time you look at a rock, see if you can also find the minerals inside it!