2 DEFINITIONIgneous rocks are formed out of hot larva or magma. The extruded larva on solidification over the earth’s surface gives rise to extrusive igneous rock. The magma on solidification below the earth’s surface is called intrusive rock.
5 INTRUSIVE IGNEOUS ROCK The molten magma under the earth’s surface gets solidify there itself to form the intrusive igneous rock.It has high pressureand temperature.it cools slowlyAlso known asplutonic rock.Granite
6 EXTRUSIVE IGNEOUS ROCK When the molten magma goes out as volcano and then solidify is known as extrusive igneous rock.It cools relatively fast.It has high temperature andpressure.Rhyolite
7 COMPLEX IGNEOUS ROCKThese rocks cools at the intermediate level that is not above or below the earths surface.Basalt
17 PRIMARY STRUCTURE Flow structure Pillow structure Blocky and ropy structureSpherulitic structureOrbicular structureRift and grain structureTension jointsVesicular structureMiarolitic structure
18 USESGranites posses excellent qualities of building rocks for structural as well as architectural purposes.They have high crushing strength.Has least porosity.Used in decorative purposes.Could get in variety of colours.