9 Different Types of Structure of rocks – Civillearners

Following are the different types of Structures:

1) Compact crystalline: 

Fine grains or particles are held together in a compact crystalline form, e.g., marble, quartzite, etc.

2) Conglomerate: 

Grains are round and of differmt size’s. they arc cemented by some binding material.

3) Foliated: 

In this type of texture, the arrangement of minerals is in the form of parallel layers.

4) Glassy: 

It is like glass without any crystal.

5) Granular crystalline : 

Crystals are of similar size.  They are separate. But binding materials, e.g., they are held together by some sandstone, gneiss, etc.

Also read: Characteristics of materials

6) Pisolitic : 

Grains are bigger in size and they are as large as peas.

7) Porous granular: 

Grains are in the form of irregular minute particles and rock with such texture is not durable.

8) Porphyritic: 

In this type of texture, crystals of one or more minerals are large and predominant.

9) Vesicular: 

This texture 1s indicated by small irregular cavities on a rock surface.

Also read: Quarrying of stones

Fracture of a rock:

The type of surface obtained, when a rock is broken, indicates its fracture. For rocks with cleavage, the breaking should be done in a direction other than that of cleavage. Fracture of rock helps to determine its texture. Fractured surfaces arc mostly irregular. Their different types are as follows:

1) Conchoidal: 

2) Earthy:

  It resembles earth, e.g., chalk.

3) Even: 

The fracture surface is more or less plane. Such a fracture denotes crystalline texture.

( 4) Fibrous: 

Fracture surfact· is in the form of fibers as m case of asbestos.

5) Hackly: 

It indicates a rough and broken surface with sharp edges.

6) Uneven: 

The fracture surface is rough due to minute elevations and depressions. Such a fracture indicates granular texture.