Post on 28-Dec-2015
Rocks and Minerals
By Kenrick Leiba
3 Kinds of Rock
• Igneous – rock that has melted and re-solidified.
• Sedimentary – Formed from sediments that have been compacted and cemented together.
• Metamorphic – Rock that has been changed by heat and pressures.
Layers of the Earth
Some revision on mixtures, compounds and elements
• An element has one kind of atom• A compound has two more kinds of
atoms in a fixture ratio• A mixture is mix of two or more
substances that are NOT bonded.
Most common Elements in the Earth’s crust
• OXYGEN-46.4%• SILICON-28.2%• ALUMINUM-8.2%• IRON-5.6%• CALCIUM-4.2%• SODIUM-2.4%• MAGNESIUM-2.3%• POTASSIUM-2%
Make up of the Earth’s Crust
How do Rocks differ from minerals?
• A mineral has a known chemical composition with a fixed ratio of elements. (could be an element or compound)• Rocks are made up of two or more
minerals.• Therefore a Rock is a solid mixture of
minerals the way cake is a mixture of eggs, flour, water etc.
How to identify Minerals
• Look at the following slides. Each shows several differ same samples of the same mineral.
• What feature might be most useful for identification. What problems might you encounter.
Examples of minerals
• Quartz
Sulphur
Hematite
Feldspar
Mica
Olivine
Some examples of rocks
• The following are some examples of different types of rocks.
Granite
Basalt
Most common minerals
• On the surface of continental crust: Quartz• In the whole crust: Feldspar• In the mantle: Olivine