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WHAT DEFINES A MINERAL
What is a Mineral A mineral, by definition, is any naturally occurring, inorganic substance, often additionally characterized by an exact crystal structure. Its chemical structure can be exact, or can vary within limits. Elements that occur naturally are also considered minerals. All minerals belong to a chemical group, which represents their affiliation with certain elements or compounds. The classified chemical groups are known as: Elements, Sulfides, Oxides, Halides, Carbonates, Nitrates, Borates, Sulfates, Chromates, Phosphates, Arsenates, Vanadates, Tungstates, molybdates, and Silicates. Some of these chemical groups have sub-categories, which may be categorized in some mineral references as separate groups. All minerals belong to various crystal structure groups, classified according to the way the atoms of the mineral are arranged. Minerals also have distinctive properties, such as color, hardness, crystal habit, specific gravity, luster, fracture, and tenacity. Many of these properties can vary among a single mineral, within limits. Many minerals exhibit certain properties that others do not, such as fluorescence and radioactivity. Minerals are an economic commodity; they are mined because of the need for a valuable element they contain or an intrinsic property they may have. Other minerals are mined for their beauty and rareness, thus giving many specimens an accepted worldwide value. There are about 3,000 different types of minerals, and new ones are constantly discovered. Most of them are not known to professional mineral collectors, because they are rare, have no economic purpose, and for the most part do not make good specimens. What is a Rock The best way to define a rock is to say that it is an indefinite mixture of naturally occurring substances, mainly minerals. Its composition may vary in containment of minerals and organic substances, and are never exact. They can range from tiny microscopic grains of minerals or organic substances to coarse agglomerates of different minerals, where the individual minerals are easily discernible. They may range in size from tiny pebbles to huge mountains. Rocks make up the earth’s crust. Many rocks are not solid -- such as magma, soil, and clay. In general, the only people interested in rocks are geologists and paleontologist who are interested in the scientific nature and dating of the rocks. Different mineral deposits can be found in related rock formations, providing use by estimating what minerals rock formations may contain.
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