Explain How Rocks Are Classified Into And How They Are Formed

Science Essay- Draft

The purpose of this report is to explain and identify the three groups that rocks are classified into and how they are formed. Rocks can be classified as Igneous, metamorphic, and sedimentary. Metamorphic rocks are formed when other rocks are hot or pressurised. The process of rocks changing is called metamorphism. Sedimentary rocks are formed by sediment that is left over time usually form the layers at the bottom of lakes and oceans. Sedimentary rocks are formed when sand, mud and pebbles get laid down in layers. These layers get squashed into more layers which eventually turn into rock. Igneous rocks are rocks that are formed when magma cools and then turns solid. Magma can transform into rocks, blown out in volcanic

Quartzite forms when a quartz-rich sandstone is heated, pressured, and chemical activity of which is metamorphism. It then recrystallizes the sand grains and then silica cement binds them together. Quartzite is likely to be smooth with a grainy and glossy appearance, and comes in various shades of pink and red due to the iron oxide. Although quartzite can sometimes appear superficially similar to marble, a piece of quartzite will not be able to be scratched by a metal blade, and quartzite will not fizz on contact with dilute hydrochloric acid. Advantages of using Quartzite as a stone tool is that The surface and texture of quartzite is quite smooth making it easy to keep clean. Because the stone is so hard, it stands up well to all kinds of weather conditions and can take regular stress. When quartzite is split, it splits through the quartz granules rather than around them as sandstone splits. This allows quartzite to be split into flat surfaces. Disadvantages of using Quartzite is that Quartzite, like any natural stone, does need some basic maintenance. Stone tools were and still are important to Indigenous Australian people. The stone tools represent many years of culture and heritage. They are important to Indigenous Australian people for social, spiritual, historical and commemorative