Basic types of rocks

There are three main types of rocks

1. Igneous rocks
2. Sedimentary rocks 
3. Metamorphic rocks    

1. Igneous rocks

Igneous rocks are form directly from the solidifying of magma. (Hydrothermal or hot viscous liquid)

In the interiors of earth there is magma in inner and outer mantle and core of earth h (they are the layers of earth) magma having temperature from 600 to 1400 Celsius. When it comes out to earth surface it quickly solidify due to sudden change in temperature and make crystals.

There are two main types  of igneous rock

1. intrusive igneous rocks 

These rocks are form below the earth surface containing large bodies in kilometres because as the magma cools below the earth surface slowly so rocks get time to grow larger and they have course grain size and large in size

2.Extrusive rocks

These type of rocks s7olidify quickly above earth surface, as magma rises upward and expose to atmosphere  it suddenly crystallize due to extremely low temperature as compare to magma and make glassy structures to fine grains

2. Sedimentary rocks

Sedimentary rock are form from the sediments of any igneous , sedimentary metamorphic rocks these sediment also contain mineral and organic matters. These sediments  deposits subsequently to the ocean floor . Sedimentary rocks have the layered structure. These layers can be use for age determination .
Process sediment are form due to physical weathering and the  these sediments collect in the river and these river forward these sediments to the oceans then these sediments subsequently settle down on sea floor of sea after millions of year they are become sedimentary rocks.

3.Metamorphic rock 

Metamorphic rocks are form through providing pressure and temperature to the rock. Their Protholits rocks(parent rocks) can be igneous or sedimentary rocks .
Metamorphic rock form within the earth crust through the process of metamorphism .