Stone Case

Stone

In geology, stones are known as rocks. Stones are generally classified by mineral and chemical composition, by the type of the constituent particles and by the process that formed the stones.

Stones have been used as the building materials for thousands of years. This is because stones have great durability, stronger strength, cheap and naturally good looking. Different kinds of stones are being selected based on the following criteria to be used as the building materials:

1. Chemical composition of stones

The chemical properties and composition of stones must be tested and verified because different elements and compounds in stones have different properties. For instance, magnesium in limestone causes it to be stronger and is called Dolomite. Whereas presence of Mica, even less than 2-3% makes stones unsuitable for building purposes. Stones with silicate as cement materials are resistant to weathering.

2. Strongness and hardness

The more compact grained and heavier a stone, the stronger it is. The strongness and hardness of stones are depending on the following factors:

a. Hardness and softness of the components

Stones containing silicon, sodium, potasium are poor while that containing magnesium, calcium, and iron are good, as they are harder. If the stone is composed of soft and unhardened materials, it will result in a soft material and vice versa.

b. Proportion of hard and soft materials

The greater the amount of hard materials, the stones will be more resistant to the weather.

c. Size and shape of materials in stones

d. Cohesion

Cohesion is the property of atoms or particles to attract each other. The fine grains have more cohesive power than the coarse grains. The greater the cohesion in stone causes the increase in the hardness, strongness and toughness of stones.

e. Porosity

Porosity is the property of a substance in which it contains pores in it. It also reduces the resistance to a point load. Stones in wet condition required a lower compression strength than normal to crush it.

f. Density

If a stone has high density and compact, it will have higher strength.

g. Comenting material

Stones with silicates as cementing material will be resistant to weathering than those with calcareous or ferruginous binding material.

3. Resistance to heat

The stones which have resistance to heat are required to have low amount of expansion due to large increase