Rocks and Minerals

Junior Science

Rocks and Minerals

• Rocks may not be alive, but they can still tell us quite a lot about the past.

• Geology is the study of the Earth, its rocks, minerals, volcanoes, earthquakes, fossils etc.

• Mineralogy is a branch of geology that studies minerals.

Minerals• A mineral is a naturally

occurring substance with its own particular chemical composition & structure.

• Minerals are found in the Earth’s crust (lithosphere) in beautiful shapes called crystals.

• Quartz, mica and feldspar are examples of minerals.

• Minerals are the building blocks that make up rock.

Characteristicsof minerals

• Minerals have several characteristics or properties that help geologists differentiate between them:

• Crystal structure• Pigment and streak• Hardness

Crystal Structure

• Many minerals have a distinctive crystal structure

• Eg. Wulfenite has flat crystals

Rocks

• The study of rocks is a branch of geology known as petrology.

• A rock is made up of minerals. Granite is a rock made from three minerals—quartz, mica and feldspar.

Ores

• Ores are rocks or minerals that contain elements that may be extracted for profit.

• Iron, for example, is extracted from an ore called haematite.

• Aluminium is extracted from the ore bauxite.