Classification of Rocks

 There are mainly three types of classification 

   a) Geological 

   b) Physical 

   c) Chemical

a) Geological classification:

Classification based on the formation of rocks 

          I. Igneous rocks: These rocks are formed by cooling of Magma. 

They are classified into two 

i) intrusive rocks : These are formed inside the earth surface 

Hypabyssal rocks: Stones formed at shallow depth from Earth's surface. E.g.. Dolorite 

Plutonic rock: Stones formed at considerable depth from the Earth's surface. E.g. Granite

ii) extrusive rocks : These are formed outside the Earth's surface. E.g. Basalt, Trap

            II. Sedimentary rocks : These are formed by the depositions of weathering products of pre existing rocks.

Eg. Sandstone, Limestone, gypsum, Gravel

            III. Metamorphic rocks: These rocks are formed by changing the character of pre existing rocks 

Eg. Quartzite, slate, marble, Gneiss

b) Physical classification 

           I. Stratified rocks: These rocks have definite plane of stratification 

Eg. All sedimentary rocks 

         II. Unstratified rocks: These rocks have no specific stratification. They are crystalline, granular or compact structure 

Eg. All igneous rocks

        III. Foliated rocks: These rocks have a tendency to split along a definite direction.

Eg. All metamorphic rocks 

c) Chemical classification 

           I. Siliceous rock: silica is the predominant constituents in this type of rocks. They are hard, durable and not easily affected by weathering

Eg. Granite, Quartzite 

          II. Argillaceous rock: clay is the predominant constituents. These are dense, compact or maybe soft

E.g.. slate, laterite

          III. Calcareous rock: calcium carbonate is the predominant constituent. 

Eg . Limestone, marble

Building Stones

 

Stone is a naturally available building material  which has been used from the early age of civilization.  It is available in the form of rocks, which is cut to  required size and shape and used as building block.

Crushing strength of common stones

 

What is Civil Engineering?

 Civil engineering is a professional engineering discipline that deals with the design, construction, and maintenance of the physical and naturally built environment, including public works such as roads, bridges, canals, dams, airports, sewerage systems, pipelines, structural components of buildings, and railways.