Page 1 - Class-8-Geo-Chap-3-Mineral & Power-Subtopic-1- Mineral,Type,Extract-LN
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SAI INTERNATIONAL SCHOOL, BHUBANESWAR.
                                Class VIII: SOCIAL STUDIES – GEOGRAPHY

                           CHAPTER - 3- MINERAL AND POWER RESOURCES

                                               (VIRTUAL CLASSES)




                             NOTES FOR CHAPTER-3- Mineral and Power Resources

        SUBTOPIC-  INTRODUCTION.- TYPES OF MINERALS AND EXTRACTION


        Minerals are naturally occurring substances that have a definite chemical composition.

           ➢  Minerals are formed in different types of geological environments, under varying natural
               conditions such as evaporation of water, extreme heat and pressure.
           ➢  Minerals can be identified on the basis of their
                  ❖  physical properties such as colour, density, hardness
                  ❖  chemical property such as solubility
           ➢  Minerals are also found in rocks and sea bed. (see book)


         TYPES OF MINERALS

            A.  On the basis of composition, minerals are classified into:-
               I.      Metallic minerals - contain metals in raw form; are of two types:
               ▪      Ferrous-- contain Iron
               ▪      Non-ferrous-- do not contain iron but may contain some other metals like gold,
                      silver, copper or lead
               ▪      Metals are hard substances that conduct heat and electricity and have lustre or
                        shine. For example, iron ore and bauxite.
               II.     Non-metallic minerals-- do not contain metals.  Examples are limestone, mica,

                       gypsum, coal and petroleum.
            B.  EXTRACTION OF MINERALS: - Minerals are mostly found in the form of ores and need to

               be extracted and purified before being used. Mining needs cheap labour and resources to
               extract it off.

            C.  There are three methods to extract minerals.
                   I.  Mining
                          ▪  is the process of taking out minerals from rocks that are buried under the
                              earth’s surface. It includes two methods

                      1.     Open cast mining-- minerals are taken out from the shallow depths by
                             removing the surface layer

                      2.     Shaft mining - deep bores/vertical tunnels called shafts are dug into the
                             ground to reach the mineral deposits that are deep under the soil layer.
                   II.  Drilling- is where deep wells are bored to take the minerals out.

                   III. Quarrying - is where minerals that lie near the surface are simply dug out.

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