ROLL NO: 07
On an auspicious day, sometime around a million years ago, a member of the Homo habilis species stood erect and walked steadily on his two feet and his two hands became totally free. A new species – Homo erectus—began its journey on a new evolutionary track. This great change took around four million years after his ancestors – the hominids — broke free from the lineage of apes and chimpanzees. But , perhaps for the next seven to eight hundred thousand years, the descendants of that first Homo erectus kept wondering about what to do with the two free hands apart from holding bones and logs of wood. That was till someone picked up a stone and threw it to some animal – probably because he was scared and was trying to defend himself, or because he was hungry and wanted to get some flesh to eat. But unconsciously, he began the gainful use of a mineral, and unconsciously again, began the evolution of a new species –Homo sapiens, the modern man. Evolving down the generations, man learnt to be choosy in picking up the stones; he realized that all stones are not good for his needs; he tried and erred, and through innumerable trials and errors spanning over tens and hundreds of thousands of years, finally he zeroed in on a sharp-edged hard mineral that we have named flint. With the sharp edges of flint, he could tear animals for hide and flesh; and much later, he could make knives and axes and spear heads. Flint became the backbone of economy. He began digging the earth, taking out new treasures and burning them. Thus was produced, some 6000 years ago, a new mineral, and from that a new material to which, much later, we have given the name copper metal. And that day began the Copper Age. In fact, this was the beginning of both mining and metallurgy. Not satisfied with copper any longer than a few hundred years, he began experiments with other metallic ores like tin, zinc and lead, and with a stroke of metallurgical genius, produced bronze. In the next two thousand years, by now, he knew about gold and silver also — not so much for industrial usage, but more for ornaments and amulets. Then came that wonder metal called iron. Man entered not only the Iron Age, but also what is known as the New World. Iron continues to be the backbone of economy even today, supported not just by copper, tin zinc, lead, gold and silver, but by a host of other metals. Although flint has survived the ages and still lives today — in name at least — in some cigarette lighters, we no longer use it for getting energy. Coal, petroleum, natural gas and uranium are the sources of energy now. But compared to the thousands of years of history of copper, lead, zinc tin, gold, silver and iron, the oldest amongst these energy minerals i.e., coal, has come to our life in a big way, only within the past 400 years or so. And we must not forget that for mining and using these energy minerals — and, in fact, all the minerals that we use today – we need machines, we need metals, we need metallic minerals – in America, in Europe, in China, in India. Even if we do not mine the metals, they still enter from soil into plants and through plants into the cells, tissues and organs of human bodies, to help the humans live healthily. Such is the importance of metals and metallic minerals in industry, in economy and in human life. From any mineral we do not get a metal. The minerals, from which we get metals, are called ores. Amongst the ores, there are many which are used only for extraction of metals, and there is no other use of them. There are also a few ores which have multiple uses. Of course the most important use is to extract their metal contents, but they can also be used straightaway for making industrial products. As a matter of convention, these are called metallic minerals in economic and statistical circles, to distinguish them from energy minerals and industrial minerals, which are not at all used for...