The bulk of the minerals formed in the bowels of the earth. Minerals are substances that are part of the earth's crust and has an inorganic base. In nature they are found in the form of crystals.
Currently, there are more than 5 thousand of minerals and their varieties. They are usually divided into two groups: metal (red iron ore, copper ore, bauxite) and nonmetallic (quartz, asbestos, calcite).
Gemstones, or as they are otherwise called, the gems are minerals. These include emeralds, rubies, diamonds, garnets and many others.
All minerals have a definite structure and chemical composition. Their characteristics do not depend on the place of occurrence. Minerals are members of various rock. For example, granite is composed of feldspar, mica, quartz and other minerals.