Minerals and Energy Resources PDF - Study Guide

You have already learnt about rocks. sufficient concentration to make its extraction Rocks are combinations of homogenous commercially viable. The type of formation or substances called minerals. Some rocks, for structure in which they are found determin...

You have already learnt about rocks. sufficient concentration to make its extraction Rocks are combinations of homogenous commercially viable. The type of formation or substances called minerals. Some rocks, for structure in which they are found determines instance limestone, consist of a single mineral the relative ease with which mineral ores may only, but majority of the rock consist of several be mined. This also determines the cost of minerals in varying proportions. Although, extraction. It is, therefore, important for us over 2000 minerals have been identified, only to understand the main types of formations a few are abundantly found in most of the in which minerals occur. rocks. Minerals generally occur in these forms: A particular mineral that will be formed (i) In igneous and metamorphic rocks from a certain combination of elements minerals may occur in the cracks, depends upon the physical and chemical crevices, faults or joints. The smaller conditions under which the material forms. occurrences are called veins and the This, in turn, results in a wide range of colours, larger are called lodes. In most cases, hardness, crystal forms, lustre and density that they are formed when minerals in liquid/ a particular mineral possesses. Geologists use molten and gaseous forms are forced these properties to classify the minerals. upward through cavities towards the earth’s surface. They cool and solidify as Study of Minerals by Geographers they rise. Major metallic minerals like tin, and Geologists copper, zinc and lead etc. are obtained Geographers study minerals as part of the from veins and lodes. earth’s crust for a better understanding of (ii) In sedimentary rocks a number of minerals landforms. The distribution of mineral occur in beds or layers. They have been resources and associated economic activities formed as a result of deposition, are of interest to geographers. A geologist, accumulation and concentration in however, is interested in the formation of horizontal strata. Coal and some forms of minerals, their age and physical and iron ore have been concentrated as a result chemical composition. of long periods under great heat and pressure. Another group of sedimentary However, for general and commercial minerals include gypsum, potash salt and purposes minerals can be classified as under. sodium salt. These are formed as a result of evaporation especially in arid regions. MODE OF OCCURRENCE OF MINERALS (iii) Another mode of formation involves the Where are these minerals found? decomposition of surface rocks, and the Minerals are usually found in “ores”. The removal of soluble constituents, leaving term ore is used to describe an accumulation a residual mass of weathered of any mineral mixed with other elements. material containing ores. Bauxite is The mineral content of the ore must be in formed this way. Fig. 5.1 MINERALS AND ENERGY RESOURCES 43 Reprint 2024-25