Minerals Essay - Four Requirements to Be Classified

There are four requirements that must be met in order for a material to be classified as a mineral. These requirements include that a substance must be a naturally occurring solid, must be formed by inorganic processes, the substance must also have characteristic crystal structure, and a specific chemical composition.

Minerals can be told apart by their physical properties and characteristics. These properties and characteristics include luster, form and habit, hardness, tendency to break in preferred directions, color, and specific gravity or density. The luster includes determining dullness or shine that is evident in the mineral. Form and habit include the shape of the mineral and its hardness can be measured by resistance to scratching, such as the test performed in the virtual lab with a penny and knife. A mineral's tendency to break in preferred directions is tested in the cleavage and fracture test that is also performed in the lab. A fracture break is rough edged and inconsistent in its break, while cleavage his clean, linear lines when broken. The color of the mineral is not always the best determining factor, as other factors can impact the color surrounding the actual mineral and mislead one to make an incorrect assumption. In this instance, the streak test produces a more reliable means of identifying the mineral through the thin layer of mineral produced in this test. Finally, specific gravity or density can be measured in the water test that measures the heaviness of the mineral.

One of the major differences between minerals and rocks is there value. While minerals are often assigned economic value in cases such as diamonds, rubies, and sapphires, rocks provide sustainability in the form of soils that can be used in planting of crops and such. There are more scientific reasons that also differentiate the two. Minerals are formed by inorganic processes and are naturally occurring solids with a unique crystal structure. For the most part, minerals have a fixed composition and are formed in an atomic lattice structure. Rocks are more complex assemblages of minerals that are sometimes mixed with other natural materials. They are formed by the solidification of magma or deposition of many layers of sediment. Other rocks can be formed as a result of high temperature, pressure, or both, and are held together by the interlocking of grains.