Rocks

Ahmed Ali Khan – VI B, DMIS

General Information about ‘Rocks’

• Rocks are the materials of which mountains, cliffs and the ground are made. Even sand, clay and soil are types of rock made from tiny particles.

• All rocks can be divided into three main groups - igneous, sedimentary and metamorphis rocks - according to the way in which they were formed.

Sedimentary•Sedimentary

rock is one of the three main rock types.

•Sedimentary rock is formed by deposition and consolidation of mineral and organic material and from precipi-tation of minerals from solution.

Igneous•Igneous rock is one of the three main rock types (the others being sedimentary and metamorphic rock).•Igneous rock is formed by magma (molten rock) being cooled and becoming solid

Metamorphic•Metamorphic

rock is the there main rock types (the others being sedimentary and metamorphic rock). •Metamorphic rocks make up a large part of the Earth's crust and are classified by texture and by chemical and mineral assemblage

Marble• Marble is a non foliated metamor-phic rock resulting from the metamor-phism of limestone, composed mostly of calcite

• It is extensively used for sculpture, as a building material, and in many other applications.

Granite• Granite (pronounced is a common and widely occurring type of intrusive, felsic, igneous rock.

• Granite is formed from the slow cooling of high silicate magma intrusions that have risen through the crust and formed large bulbous chambers of molten material called plutons

•Quartz is the second most abundant mineral in the Earth's continental crust.

•It is made up of a continuous framework of SiO4 silicon-oxygen tetrahedra.

Quartz

limestone•Limestone is a sedimentary rock composed largely of the mineral calcit.

•The deposition of limestone strata is often a by-product and indicator of biological activity in the geologic record.