Mineral in general is any naturally stirring chemical constituent or compound, however in mineralogy and geology, chemical fundamentals and compounds that has been created through dead processes. Petroleum and coal, which are formed by the decomposition of organic matter, are not minerals in the strict sense. More than 3000 mineral species are known, most of which are characterized by definite chemical composition, crystalline structure, and physical properties. They are classified primarily by chemical composition, crystal class, hardness, and appearance (color, luster, and opacity). Mineral species are, as a rule, limited to solid substances, the only liquids being metallic mercury and water. All the rocks forming the earth's crust consist of minerals. Metalliferous minerals of economic value, which are mined for their metals, are known as ores. The mineral name itself is a link to the description of that mineral species, while the number to the left is the approximate count of the number of specimens currently available for sale of that species, and is also a direct link to the list of specimens. (Clydesdale, F.M)
Minerals form through natural processes within the earth, including volcanic eruptions, precipitation of a solid out of a liquid, and weathering of pre-existing minerals. At present, scientists, engineers and manufacturers produce a lot of ceramics, plastics and additional substances with a precise chemical composition and structure, however none of these synthetic substances is considered a true mineral. Liquids and gases are not considered minerals, in large part because their structure is continuously altering, which means they do not have a distinguishing crystal arrangement. Any material produced through organic activity such as leaves, bones, peat, shell or soft animal tissue is not considered a mineral. Fossils, although they were once living, have generally had their living tissues completely replaced by inorganic processes after burial; thus, they are considered to be composed of minerals as well.........
