The blog presents the important summary notes from the Chapter 3, Mineral and Power Resources, Geography , NCERT of Class 8. This can be used for school studies as well as for Competitive entrance exams and Olympiads.
1. Mineral : A naturally occurring substance that has a definite chemical composition is a mineral.
2. Minerals are not distributed evenly over space, but are concentrated in a particular area or rock formations.
3. Minerals are created by natural processes without any human interference.
4. Minerals can be identified on the basis of their physical properties such as colour, density, hardness and chemical property such as solubility.
5. On the basis of composition, minerals are classified mainly as :
• Metallic minerals : these contain metal in raw form.
– Ferrous minerals: iron ore, manganese and chromites.
– Non-ferrous minerals: does not contain iron but may contain some other metal such as gold, silver, copper or lead.
• Non-metallic minerals : do not contain metals.
Examples: limestone, mica and gypsum, also mineral fuels like coal and petroleum.
6. Metals are hard substances that conduct heat and electricity and have a characteristic lustre or shine.
Examples: Iron ore, bauxite, manganese ore .
7. Rock : A rock is an aggregate of one or more minerals but without definite composition of constituent of mineral.
8. Ores : Rocks from which minerals are mined are known as ores.
9. Minerals can be extracted by :
10. Mining : The process of taking out minerals from rocks buried under the earth’s surface is called mining.
11. Open-cast mining: Minerals that lie at shallow depths are taken out by removing the surface layer; this is known as open-cast mining.
12. Shaft mining: Deep bores, called shafts, have to be made to reach mineral deposits that lie at great depths. This is called shaft mining.
13. Drilling: Petroleum and natural gas occur far below the earth’s surface. Deep wells are bored to take them out, this is called drilling.
14. Quarrying: Minerals that lie near the surface are simply dug out, by the process known as quarrying.
15. Minerals occur in different types of rocks as in igneous rocks, in metamorphic rocks while others occur in sedimentary rocks.
16. Generally, metallic minerals are found in igneous and metamorphic rock formations that form large plateaus.
• Iron-ore in north Sweden,
• Copper and nickel deposits in Ontario, Canada,
• Iron, nickel, chromites and platinum in South Africa.
17. Sedimentary rock formations of plains and young fold mountains contain non-metallic minerals like limestone.
• Limestone deposits of Caucasus region of France
• Manganese deposits of Georgia and Ukraine
• Phosphate beds of Algeria
18. Mineral fuels such as coal and petroleum are also found in the sedimentary strata.