Rocks are made up of minerals. Minerals are made up of elements. Minerals are solid, have a definite chemical formula, crystalline structure, and a set of physical properties. Rocks may be sedimentary, igneous, or metamorphic. Rocks may be made up of a two or more minerals. Examples of minerals are quartz, calcite, diamond, feldspar, and hematite. Examples of rocks are granite, marble, sandstone, and shale.
We'll start from the fact that all rocks consist of two or more minerals. Therefore, the properties of rocks will be the properties of the minerals found in their structures.
The process of formation of rocks arranges the rocks within few groups:sedimentary rocks, metamorphic rocks, igneous rocks.
The minerals are identified looking at several main characteristics, such as: color,transparency,luster,crystal form, hardness, tenacity, cleavage, fracture and specific gravity.