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.