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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).





Palygorskite is named after a deposit in the Ural Mountains, Russia. The Dana's System of Mineralogy spells it Paligorskite, but since the origin is Russia, and the Russians named it, the Russian spelling would be correct. It is a magnesium, aluminum silicate mineral, and it is fibrous, if broken apart. In some local areas it is known as "Mountain Leather", because it has the feel of leather, and it is very light, despite having a SG of 2.5.

It is monoclinic, has good cleavage, is relatively soft (2), is white to grayish, yellowish or gray-green. "It occurs as a alteration product of magnesium silicates in soils and sediments; in lacustrine marls, carbonate rocks and mafic igneous rocks, in clay gouge associated with fault movement"** It is typically associated with calcite, dolomite, talc, chlorite, quartz, opal and montomorillonite. Palygorskite occurs over a wide area, including Asia, North America, Europe and Africa.

It has been studied as a substitute for asbestos, but I know of no commercial uses. However, it can be a part of many clays, including bentonite and montomorillonite, which are used widely in many industries.

** Dana's System of Mineralogy (6th Edition)