Major objective of this lecture is to present on Rocks. There are 3 types of rocks: Igneous, metamorphic and sedimentary. Some rocks have air bubbles because of the way they are formed. Rocks such as Millstone Grit have these properties and are otherwise known as Sedimentary Rocks. Crystals have a more jagged form (meaning they fit together more easily) This means there’s less air bubbles therefore its a denser rock Metamorphic and Igneous rocks have these properties. Here also briefly present on how metamorphic rocks change.