Question

How are minerals formed in igneous and metamorphic rocks?

Answer 1

• In Metamorphic and Igneous rocks, minerals may occur in the joints, faults, crevices, cracks.
• The larger ones are called lodes and smaller occurrences are called veins.
• In the majority of cases, these are formed when minerals in gaseous and molten/liquid form start moving in an upward direction, towards the surface of earth, through cavities.
• As they rise upwards, they start cooling and solidifying.
• Important metallic minerals like lead, zinc, copper, tin are obtained from lodes and veins.
• Many minerals exist in the form of layers or beds, in the sedimentary rocks.
• These minerals were formed due to their concentration in horizontal strata, caused by deposition and accumulation.
• Due to the long period of pressure and heat, some forms of iron and coal have been concentrated.

Formation of Minerals

• Minerals are usually found in “ores”.
• An accumulation of any mineral mixed with other elements, is described with the help of the term ore.
• To make sure that extraction of minerals are economically viable, the mineral content of the ore must be in adequate concentration.
• The relative ease with which mineral ores may be mined is determined by the type of structure and formation in which they are found.
• This also helps in determining the cost of extraction.