Igneous means fire. igneous is one of the three main rock types, the other two are sedimentary and metamorphic rocks. Igneous rock is formed through the cooling and solidification of magma or lava.


Metamorphic arise from the transformation of existing rock types, in a process called metamorphism which means "change in form". The original rock is subjected to heat (temperatures greater than 150 to 200 °C) and pressure (1500 bars), causing profound physical and/or chemical change.


1.) Limestone

2.) shale

3.) coal

4.) gypsum

5.) chert