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.