Rocks

When minerals bond they form rocks, defined as an aggregation of solid matter composed of one or more minerals.

Geologists divide them into three main categories according to where and how they were formed:

igneous rocks - metamorphic rocks – sedimentary rocks.

 1 – Rivers of fire

 2 - Pressure and heat

 3 – Layer upon layer

 4 – The rock cycle

Roks Postage Stamps