← 🌍 Earth science · usually met in Std 6-10
Three families — igneous, sedimentary and metamorphic — and a cycle that turns each into the others given enough time and pressure.
Igneous rock forms when molten rock cools: slowly underground it grows large crystals, as in granite; quickly at the surface it forms fine-grained rock like basalt. Sedimentary rock forms when fragments settle in layers and are compressed — sandstone, shale, limestone — and it is the only family that commonly contains fossils. Metamorphic rock is either of the others changed by heat and pressure without melting: limestone becomes marble, shale becomes slate.
None of it is permanent. Rock is weathered to sediment, buried, compressed, heated, lifted and weathered again. A mineral is a naturally occurring crystalline substance with a definite composition; a rock is usually a mixture of minerals.
Want to see it moving? Search YouTube for “Rocks and minerals” ↗ — we send you to the search rather than to one video, because a link to one video eventually rots.
This entry was written for Star Student in our own words — it is a summary, not a source. Here is where the people who actually hold these facts keep them. Go and check.
Your own textbook ↗Balbharati publishes the textbooks free to read online. Your chapter is the thing to check first — an encyclopedia is a summary, and the syllabus is the syllabus. Geological Survey of India ↗Rocks, earthquakes, the Himalaya and seismic zoning. India Meteorological Department ↗The monsoon, rainfall and cyclone warnings, from the department that issues them.Last gone through: 1 October 2026 · How these entries are written
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