1) Basalt and trap
 |
| basalt & trap |
– These are igneous rocks.
– The structure is medium to find grain and compact.
– Their colour where is from Dark grey to black.
– Their weight varies from 18 KN/m3 to 29 KN/m3.
– The compressive strength varies from 200 to 350 N/mm2.
– They are used as Road metals; aggregates for concrete.
– They are also used for rubble masonry work for Bridge piers river walls and Dams.
2) Granite
 |
| Granite |
– Granite are also igneous rocks.
– The color varies from light grey to pink.
– The structure is crystalline fine to coarse grained.
– Well polished and hard durability.
– Specific gravity is from 2.6 to 2.7.
– Compressive strength is 100 to 250 N/mm2.
– They are used primarily for Bridge piers river walls and for dams.
– The use of granite for monumental and institutional buildings is common.
– Polish granite are used as table tops cladding for columns and walls.
3) Sand-stone
 |
| sand stone |
– These are sedimentary rocks.
– They are found in various colours like white, grey, Red, Brown, yellow and even dark Grey.
– The specific gravity varies from 1.85 to 2.7.
– Compressive strength where is from 20 to 170 N/mm2.
– Its velocity varies from 5 to 25%.
– It is desirable to use sandstone with silica cement for heavy structures, if necessary.
– They are used for masonry work dams bridge piers and river walls.
4) Slate
 |
| slate |
– These are metamorphic rocks.
– They are composed of quartz, mica, clay minerals.
– The structure is fine grain.
– The colour varies from Dark grey, greenish grey, purple grey to black.
– The specific gravity is 2.6 to 2.7.
– Compressive strength where is from 100 to 200 N/mm2.
– They are used as roofing tiles, slabs, pavement etc.
5) Laterite
 |
| laterite |
– it is a Metamorphic rock
– It is having porous and sponge structure.
– It contain high percentage of iron oxide.
– It colours maybe brownish red yellow, brown and Grey.
– Its specific gravity is 1.85.
– Compressive strength where is from 1.9 to 2.3 N/mm2.
– When used as building stone its outer surface should be plastered.
6) Marble
 |
| marbles |
– This is a Metamorphic rock.
– It should be good polished.
– It is available in different pleasing colours like white and pink.
– Its specific gravity is 2.65.
– Compressive strength is 72-75 N/mm2.
– It is used for column flooring and steps.
7) Gneiss
 |
| Gneiss |
– It is Metamorphic rock.
– It is having fine to coarse grain.
– They are available varieties of colours like light grey, pink, purple, greenish grey, and dark Grey.
– The stones are not preferred because of deleterious constituent present in it.
– They may be used in minor construction work.
– The specific gravity where is from 2.5 to 3.0.
– crushing strength where is from 50 to 200 N/mm2.
8) Quartzite
 |
| Quartzite |
– It is a Metamorphic rock.
– The structure is fine to coarse grained.
– They are available in different colors like white, grey, yellowish.
– The specific gravity where is from 2.5 to 2.65.
– Crushing strength where is from 50 to 300 N/mm2
– They are used as building blocks and slabs.
– They are also used as aggregates for concrete.
Thank you for visiting…