4. GRANITE
โข Granite is a common variety of igneous rocks.
โข It is hard, tough and is found in variety of
colors.
โข It is used as large building blocks for heavy
engineering works such as piers, abutments
of bridges, etc.
โข It is used or constructing steps, sills and
columns.
5.
6. BASALT AND TRAP
โข These are hard and tough and are greenish
grey to dark grey in color.
โข They are more suitable as road metal, railway
ballast and as an aggregate in concrete.
โข They are also used as flag stones for paving
streets and for constructing steps.
7.
8. SANDSTONE
โข Sandstone is a common variety of
sedimentary rocks.
โข Its compact and fine grained variety is used in
ashlars masonry and other works of
architectural appearance.
โข It is also used in heavy engineering works
such as monumental buildings, dams, docks,
etc.
9.
10. LIMESTONE
โข Limestone are the common variety of
sedimentary rocks.
โข These are unsuited for external work in
industrial towns.
โข It is used in masonry walls and paving streets.
11.
12. SLATE
โข Slate is a common variety of metamorphic
rocks.
โข It is hard, tough and least absorptive and
gives ringing sound when struck with a light
hammer.
โข Being absorbent it is also used in bath,
cisterns, urinal partitions, etc.
13.
14. MARBLE
โข Marble is compact and crystalline in structure
due to which it takes a fine polish.
โข It is less durable and its absorption is 1 to 3%.
โข It is mainly used for ornamental and highly
specialized building works as in columns,
staircases, table slabs, window sill, floor
finishing, steps, etc.