Stone are obtained from naturally occurring rocks. Stone so not have a definite structure. these are commonly formed by weathering of sedimentary rocks via wind, water, and sun rays. Stone constitutes an important building material used for different structures. stone is used in foundations, columns, bedrocks, walls, etc. in buildings. Stone is also used in hydraulic structures like dams and bridges. Stone serves as strong road metal and railways.
The building stones are obtained from the rocks. They do not have any definite shape and structure. In actuality, these are fragmented parts of the rock.
Sources of Stone :
The Stone are obtained by rocks. A rock represents a definite portion of the earth’s surface. It is not homogenous and does not have definite chemical composition and shape. It is known as a monomineralic rock if it contains only one mineral and it is known as the polymineralic rock if it contains several minerals. Quartz, sand, pure gypsum, magnesite, etc. are examples of monomineralic rocks, and basalt, granite, etc. are examples of polymineralic rocks. The various rock-forming minerals are :
Classification Of Rocks :
The rocks may be classified in the following three ways :
- Geological Classification
- Physical Classification
- Chemical Classification
Geological Classification :
According to this classification, The rocks are of the following three types :
- Igneous rocks
- Sedimentary rocks
- Metamorphic rocks.
Igneous Rocks :
The rocks, which are formed by the cooling of magma are known as igneous rocks. The magma is molten or pasty rocky materials produced due to the fusion and present at the inside portion of the earth’s surface, which has a high temperature.
The igneous rocks are classified as :
(a) Plutonic Rock
(b) Hypabyssal Rock
(c) Volcanic Rock
2. Sedimentary Rocks:
These rocks are formed by the deposition of products of weathering on the preexisting rocks. The product of weathering is ultimately carried away from their place of origin by the agents of transport. These agents are rain, wind, frost, flowing water, etc. Following four types of deposits occur :
(a) Residual deposits
(b) Sedimentary deposits
(c) Chemical deposits
(d) Organic deposits
The example of sedimentary rocks is gravel, sandstone, limestone, lignite, etc.
3. Metamorphic Rocks:
These are formed by the change in the character of the pre-existing rocks. The process of change is known as metamorphism. The igneous, as well as sedimentary rocks, change their character when they are subjected to great heat and pressure. The following four types of metamorphism occur with various combinators of heat, uniform pressure, and directed pressure.
(a) Thermal metamorphism
(b) Cytostatic metamorphism
(c) Plutonic metamorphism
(d) Dynamo-thermal metamorphism