Very Short Question and Answers - Introduction of Minerals

A mineral is a naturally occurring, inorganic substance with a definite chemical composition and an ordered internal crystalline structure.

Metallic minerals: iron ore (hematite), copper; Non-metallic minerals: mica, gypsum.

Streak is the colour of the mineral in its powdered form, often more reliable for identification, while colour is the visible surface colour which can sometimes be misleading.

Lustre describes how mineral surfaces reflect light. Pyrite has metallic lustre, while quartz has a glassy (vitreous) non-metallic lustre.

Mohs scale measures the hardness of a mineral, indicating how easily it can be scratched. Talc has a hardness of 1 (softest), and diamond has a hardness of 10 (hardest).

Cleavage is the tendency of a mineral to break along flat planes, e.g., mica splits into thin sheets. Fracture is an irregular break, e.g., quartz exhibits conchoidal fracture.

Key characteristics are: naturally occurring, inorganic, definite chemical composition, ordered internal crystalline structure, homogeneous properties, and usually non-renewable.

Minerals form when magma cools and crystallizes. Examples include magnetite and chromite found near igneous intrusions and minerals like feldspar and mica in pegmatites.

Coal is formed from plant remains in swampy conditions. The Damodar valley (in Jharkhand and West Bengal) is a major coal-producing region in India.

Hydrothermal processes form mineral deposits from hot mineral-rich fluids moving through rocks. Examples are gold and copper vein deposits.

Residual concentration occurs when weathering removes soluble materials, leaving behind insoluble minerals concentrated near the surface. Bauxite forms this way in tropical climates.

Rock salt (halite) found in the Rann of Kutch and gypsum found in Rajasthan are formed from evaporation of water.

Major iron ore deposits in India are found in Singhbhum (Jharkhand), Keonjhar and Mayurbhanj (Odisha), Durg-Bastar-Chandrapur (Chhattisgarh and Maharashtra), and Bellary-Hospet region (Karnataka).

Bauxite (aluminium ore) is obtained from lateritic soils formed by intense weathering.

Sukinda valley in Odisha has large deposits of chromite, the ore of chromium.

Coal is a major mineral fuel found primarily in the Damodar valley (Jharkhand and West Bengal) and Godavari valley (Telangana and Andhra Pradesh).

Mica is identified by its perfect cleavage into thin, flexible sheets and its pearly lustre.

Minerals are considered non-renewable because they form over geological time periods, making them unable to be replaced quickly after extraction.

Karnataka is known for gold mining, with important mines at Hutti and the historically significant Kolar mines.

Phosphorite is a mineral formed biologically and is found along the coast of Andhra Pradesh in India.