Key Points

A mineral is a homogenous, naturally occurring substance with a definable internal structure. Rocks are combinations of one or more minerals, with some like limestone consisting of a single mineral.

In igneous and metamorphic rocks, minerals occur in cracks, crevices, or joints. Smaller occurrences are called veins and larger ones are called lodes, containing minerals like tin, copper, zinc, and lead.

In sedimentary rocks, minerals are found in beds or layers formed by deposition and accumulation. This includes minerals like coal, iron ore, gypsum, and potash salt.

Bauxite, the ore of aluminum, is formed through the decomposition of surface rocks. This process leaves a residual mass of weathered material containing the ore.

Placer deposits are accumulations of valuable minerals formed in alluvial deposits in valley floors and at the base of hills. They typically contain minerals not corroded by water, such as gold, silver, and platinum.

Iron ore is the backbone of industrial development. Magnetite is the finest quality ore with high iron content, while Hematite is the most important industrial iron ore by quantity used.

India's major iron ore belts are the Odisha-Jharkhand belt, Durg-Bastar-Chandrapur belt in Chhattisgarh and Maharashtra, Ballari-Chitradurga-Chikkamagaluru-Tumakuru belt in Karnataka, and the Maharashtra-Goa belt.

India is deficient in copper, used in electrical industries, with mines in Balaghat (MP) and Khetri (Rajasthan). Bauxite is the ore for aluminum, and Odisha is its largest producing state.

Mica is vital for electric industries due to its insulating properties, with major deposits in Jharkhand. Limestone is a key raw material for the cement industry and is found in sedimentary rocks.

Mining poses serious health risks to miners, such as pulmonary diseases, and environmental damage. It leads to land degradation, water contamination, and air pollution from dust.

Conventional energy sources are non-renewable and have been in use for a long time, such as coal, petroleum, natural gas, and electricity from thermal and hydel power.

Non-conventional sources are renewable and are being developed to reduce pollution and dependence on fossil fuels. These include solar, wind, tidal, geothermal, biogas, and atomic energy.

Coal is India's most abundant fossil fuel, found in two main geological ages: Gondwana (metallurgical coal) and Tertiary (in north-eastern states). Anthracite is the highest quality hard coal.

Petroleum is a major energy source found in anticlines and fault traps in tertiary rock formations. Major production areas are Mumbai High, Gujarat, and Assam, which is the oldest oil-producing state.

Nuclear energy is generated by altering the structure of atoms using Uranium and Thorium. The Monazite sands of Kerala are rich in Thorium.

As a tropical country, India has immense potential for solar energy. The largest wind farm cluster is located in Tamil Nadu, stretching from Nagarcoil to Madurai.

Geothermal energy harnesses heat from the Earth's interior, with projects in Puga Valley, Ladakh. Tidal energy uses ocean tides and has potential in the Gulf of Khambhat and Gulf of Kuchchh.

Developing a sustainable path for energy is crucial. This involves promoting energy conservation and increasing the use of renewable energy sources, based on the principle that 'energy saved is energy produced'.