The rocks are the naturally occurring solid materials or the agglomeration of minerals forming the earth’s crust or lithosphere. The word ‘lithosphere’ means a ‘sphere of rock’ or ‘rock sphere’. These rocks are made up of single or more minerals.
A rock does not necessarily look like a hard, massive-sized stone; at times, it may be soft small textured particles like mud, clay, sand etc. A small unit of the rock is called an element.
The rocks based on the origin are categorized into three major types: Igneous, Sedimentary and Metamorphic.