STONE
❑ Stones arenaturally occurring compact, solid & massive material that
make the crust of the earth
❑Stones are technically rocks which are in use since time
immemorial(ancient).
7.
Classification of rocks
1.Geological 2. Physical 3. Chemical
Geological classification : -
1. Igneous rock 2. Sedimentary rock 3.Metamorphic rock
❑Rocks formed by cooling & solidification of magma or lava.
❑These rocks are strong & durable
❑They have crystalline & compact grains
Igneous rock is of two types : -
a) Intrusive rock b) Extrusive rock
Ex- Hypo basal(Dolerite), Ex- Volcanic rock (basalt)
Plutonic rock( Granite)
8.
MAGMA- inside earth’ssurface
LAVA- Outside earth’s surface
Intrusive Igneous Rocks
When cooling & crystallization of magma occurs deep inside earth surface.
1. Plutonic Rocks
- When magma cools deep inside earth
- Ex- Granite
2. Hypobassel Rocks
- When magma cools at shallow depth
- Ex- Gabbro, diorite, pegmatite etc.
9.
Extrusive Igneous Rocks
Whencooling & crystallization of magma occurs on top of earth surface.
- Ex- Basalt, trap, Andesite, Dacite, Rhyolite etc.
Sedimentary Rocks
These rocksare formed by weathering of pre-exiting rock by external
agencies such as wind, air, water etc.
1. Mechanical (Clastic) Sedimentary Rocks:
- These rocks are formed due to physical weathering by external agencies
such as running water, moving air etc.
- Ex- Sandstone, Shale, Gravel, Sand, Mud stone, Silt stone, Breccia,
Conglomerate
2. Chemical Sedimentary Rocks :
- These rocks are formed by chemical action of water, acids, alkalies etc.
- Ex- Gypsum, Clay, Limestone, Dolostone, Evaporites, dolomite etc.
12.
Sedimentary Rocks
3. Biological(Organic) Sedimentary Rocks :
- These rocks are formed by remains of organisms such as sea animals
- Ex-Coal, Chert etc.
Metamorphic Rocks
❑ Theserocks are formed when pre-existing rocks have been changed in
texture and composition by increased temperature and pressure.
❑ Igneous rocks
Sedimentary rocks
Metamorphic rocks
High Temperature & Pressure
15.
Metamorphic Rocks
1. FoliatedRocks
❑ These rocks have bands or strips on there surface throughout there body
❑ Ex- Slate, Schist, Gneiss etc.
2. Non-foliated Rocks
❑ These rocks do not have bands or strips on their surface or body
❑ Ex- Quartzite , Marble etc.
16.
STONE TYPE AFTER
METAMORPHISM
GraniteIGNEOUS Gneiss
Basalt IGNEOUS Laterite
Limestone Sedimentary Marble
Sandstone Sedimentary Quartzite
Mud stone (Shales) Sedimentary Slate