What is it? - Igneous is a type of rock that is formed when hot magma cools. The magma is made of melted minerals and turns into crystal –like rocks Igneous is ALWAYS formed by the process of melting There are two types of igneous rock - volcanic: magma that cools outside volcano -plutonic: magma that cools inside the volcano Ex. Granite, Pumice, etc.
What’s That? - Sedimentary rock is formed when sediment ( tiny pieces of the earth) is weathered/ eroded and washed down rivers and streams. When it reaches the bottom of the waterbed the sediment is compressed by the weight of water and more sediment until it forms into rock. Ex. Limestone, Sandstone, etc.
Like Igneous rock, the sedimentary rock is also distinguished by it’s process of formation - Sedimentary Rock is ALWAYS formed through weathering and erosion There are three types of Sedimentary rock -Clastic : The most common; formed by little bits of rock -Organic: formed from sedimentary debris as well as calcium -chemical: formed when standing water evaporates leaving mineral behind
Metamorphic rock is simply igneous or sedimentary rock that has taken on a new form through the process of heating and pressurization. Ex. Schist, gneiss