2. A natural material of construction which is
obtained from rocks by suitable method is
called a stone.
3. The stone which is used for construction of
engineering structures is known as
building stone .
4. Marble, granite and sandstone are used
for facing work of buildings.
Limestone and sandstone are used for
general building works.
Fine-grained granite, marble, and
soft sandstone are used for Carvings and
ornamental works.
Compact limestone and sandstone are
used for Fire-resistant masonry
5. An aggregate of minerals which form the
earth’s crust is known as rock.
6.
7. It is based on the mode of formation of
rocks is known as geological classification.
a) igneous rock
b) sedimentary rock
c) metamorphic rock
8. Igneous rock is formed directly by
solidification of molten material,either
inside or on the surface of earth are called
Igneous rock.
It is also called primary rocks.
Example :-granite , basalt ,trap , etc.
9. The rocks formed by the consolidation of
particles of the pre-existing rocks under
the particles of the weathering agencies
such as wind ,running water ,glaciers etc
as know as sedimentary rocks.
Its is also called secondary rocks .
Example :- sand stone ,lime stones etc.
10. The rocks formed from the pre-existing
rocks within the earth crust under the
influence of variation in temperature or
both are called metamorphic rocks.
example :- marble ,slate ,gneiss etc.
11. It is based on the pysical properties i.e
structure of rocks .
a) un-stratified rocks
b) stratified rocks
c)foliated rocks
12. The rocks which do not show destine signs
of layers and cannot ne easily splinted up
into layers are called un-stratified rocks.
Example:-granite , basalt ,trap etc.
13. The rocks which show distinct sign of
layers and can be easily splitted up into
layer are called stratified rocks.
Examples :- sand ,lime stone etc.
14. The rocks which can be splitted up into
thin sheets are known as foliated rocks.
Example :- slate schist etc.
15. It is based on the chemical composition of
rocks.
a) siliceous rock.
b) argillaceous rock.
c) calcareous rock.
16. The rocks having silica (SiO2) or sand as
their major constituent are called siliceous
rock.
Example :- sand stone ,granite etc.
17. The rocks having alumina (Al2O3)or clay
as their major constituent are called
argillaceous rock.
it is hard like slate or soft like mudstone.
18. The rocks having calcium carbonate
(CaCo3)or lime as their major constituent
are called Calcareous rocks.
Example :- lime stone ,marble ,kankar
etc.