A mineral is a naturally occuring, homogeneous, solid with a crystalline atomic structure. Crystallinity implies that a mineral has a definite and limited range of composition, and that the composition is expressible as a chemical formula. Some definitions of minerals give them as inorganic materials, however both diamonds and graphite are considered minerals, and both are primarily comprised of carbon, which would make them organic. So this leads me, as an engineer, to believe that mineralogists do not have a good, precise definition of a mineral, but rather a loose definition. The definition above, is the most inclusive and would include all substances currently described as minerals. The key items that make something a mineral are occurring naturally, and the definite crystal structure, that is expressible as a chemical formula. Rocks that do not meet this criteria are referred to as amorphis - not having a definite structure or expressible as a chemical formula. Some elements that occur naturally and are minerals are arsenic, bismuth, platinum, gold, silver, copper, and sulphur.
THE DEFINITION OF ORGANIC: Organic chemistry is the study of those substances containing carbon in combination with hydrogen (H), and a few other non metals, namely oxygen (O), nitrogen (N), sulfur (S) and the halogens (F2, Cl2, Br2, and I2).
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The Element, Sulfur, like most elements lighter than iron, is believed to have been created by the nuclear fusion
of lighter elements in the interior of stars. On Earth, it is widely distributed in its elemental state as a secondary
mineral or as a volcanic deposit, as well as in combination with a number of metals. Large sedimentary deposits of the almost pure element, mainly of Tertiary age, are found in the coastal regions of Texas and Louisiana; on the Isthmus of Tehuantepec, Mexico; and in Sicily. Sulfur occurs in some fossil fuels, most notably coal, in chemical combination with carbon and other elements; its removal is difficult. Sulfur is prevalent in the sulfide ores of important metals: iron pyrite, sphalerite (zinc sulfide), and galena (lead sulfide). It is also found in calcium sulfate (gypsum) and barium sulfate (barite). The magnesium and sodium sulfates are present in ocean water and in many mineral waters. Sulfur occurs in living plant and animal tissue as part of the chemical makeup of the amino acids cysteine, cystine, and methionine. Organic sulfur compounds occur in garlic, mustard, onions, and cabbage and are responsible for the odor of skunks. |