MineralsGroup1

Minerals- Any of a class of substances occurring in nature, usually comprising inorganic substance

[] <-- deffinition of minerals. [] <-- list and explination of all minerals by alphabet [] <-- the link to formulas of some minerals possible to use as examples to show how to tell what families they are in by looking at the formula.

__Characteristics of a Mineral:__
 * //1. COLOR//**-the quality of an object or substance with respect to light reflected by the object, usually determined visually by measurement of hue, saturation, and brightness of the reflected light; saturation or chroma
 * //2. DENSITY//**-the state or quality of being dense; compactness; closely set or crowded condition
 * //3. FEEL//**-to perceive or examine by touch
 * //4. HARDNESS-//**the state or quality of being hard
 * 5.** Minerals are **//inorganic//** or non living.



__Chemical Properties of a Mineral and Mineral Families__ : //**SILICITE CLASS:**// The largest group of minerals by far are the silicates (most rocks are ≥95% silicates), which are composed largely of silicon and oxygen, with the addition of ions such as aluminium, magnesium, iron, and calcium. Some important rock-forming silicates include the feldspars, quartz, olivines, pyroxenes, amphiboles, garnets, and micas. //**CARBONATE CLASS:**// The carbonate minerals consist of those minerals containing the anion (CO3)2- and include calcite and aragonite (both calcium carbonate), dolomite (magnesium/calcium carbonate) and siderite (iron carbonate). Carbonates are commonly deposited in marine settings when the shells of dead planktonic life settle and accumulate on the sea floor. Carbonates are also found in evaporitic settings (e.g. the Great Salt Lake, Utah) and also in karst regions, where the dissolution and reprecipitation of carbonates leads to the formation of caves, stalactites and stalagmites. The carbonate class also includes the nitrate and borate minerals. //**SULFATE CLASS:**// Sulfate minerals all contain the sulfate anion, SO42-. Sulfates commonly form in evaporitic settings where highly saline waters slowly evaporate, allowing the formation of both sulfates and halides at the water-sediment interface. Sulfates also occur in hydrothermal vein systems as gangue minerals along with sulfide ore minerals. Another occurrence is as secondary oxidation products of original sulfide minerals. Common sulfates include anhydrite (calcium sulfate), celestine (strontium sulfate), barite (barium sulfate), and gypsum (hydrated calcium sulfate). The sulfate class also includes the chromate, molybdate, selenate, sulfite, tellurate, and tungstate minerals. //**ULFIDE CLASS:**// Many sulfide minerals are economically important as metal ores. Common sulfides include pyrite (iron sulfide – commonly known as fools' gold), chalcopyrite (copper iron sulfide), pentlandite (nickel iron sulfide), and galena (lead sulfide). The sulfide class also includes the selenides, the tellurides, the arsenides, the antimonides, the bismuthinides, and the sulfosalts (sulfur and a second anion such as arsenic). //**PHOSPHATE CLASS:**// The phosphate mineral group actually includes any mineral with a tetrahedral unit AO4 where A can be phosphorus, antimony, arsenic or vanadium. By far the most common phosphate is apatite which is an important biological mineral found in teeth and bones of many animals. The phosphate class includes the phosphate, arsenate, vanadate, and antimonate minerals. //**ELEMENT CLASS:**// The elemental group includes metals and intermetallic elements (gold, silver, copper), semi-metals and non-metals (antimony, bismuth, graphite, sulfur). This group also includes natural alloys, such as electrum (a natural alloy of gold and silver), phosphides, silicides, nitrides and carbides (which are usually only found naturally in a few rare meteorites). //**ORGANIC CLASS:**// The organic mineral class includes biogenic substances in which geological processes have been a part of the genesis or origin of the existing compound. Minerals of the organic class include various oxalates, mellitates, citrates, cyanates, acetates, formates, hydrocarbons and other miscellaneous species. Examples include whewellite, moolooite, mellite, fichtelite, carpathite, evenkite and abelsonite.
 * //HALIDE CLASS://** The halide minerals are the group of minerals forming the natural salts and include fluorite (calcium fluoride), halite (sodium chloride), sylvite (potassium chloride), and sal ammoniac (ammonium chloride). Halides, like sulfates, are commonly found in evaporite settings such as playa lakes and landlocked seas such as the Dead Sea and Great Salt Lake. The halide class includes the fluoride, chloride, bromide and iodide minerals.
 * //OXIDE CLASS://** Oxide minerals are extremely important in mining as they form many of the ores from which valuable metals can be extracted. They also carry the best record of changes in the Earth's magnetic field. They commonly occur as precipitates close to the Earth's surface, oxidation products of other minerals in the near surface weathering zone, and as accessory minerals in igneous rocks of the crust and mantle. Common oxides include hematite (iron oxide), magnetite (iron oxide), chromite (iron chromium oxide), spinel (magnesium aluminium oxide – a common component of the mantle), ilmenite (iron titanium oxide), rutile (titanium dioxide), and ice (hydrogen oxide). The oxide class includes the oxide and the hydroxide minerals.
 * //STRUNZ CLASS://** a scheme for categorizing minerals based upon their chemical composition.
 * //DANA CLASS://** a chemical mineral classification system.



__Physical Properties of Minerals:__ Hardness, luster, color, streak, cleavage and fracture are all physical properties of minerals //FRACTURE//: describes how a mineral breaks when broken contrary to its natural cleavage planes.
 * //COLOR://** indicates the appearance of the mineral in reflected light or transmitted light for translucent minerals (i.e. what it looks like to the naked eye)
 * //STREAK//:** refers to the color of the powder a mineral leaves after rubbing it on an unglazed porcelain //streak plate//. Note that this is not always the same color as the original mineral..
 * //CLEAVAGE//:** describes the way a mineral may split apart along various planes. In thin sections, cleavage is visible as thin parallel lines across a mineral.
 * //LUSTER://** the state or quality of shining by reflecting light; glitter, sparkle, sheen, or gloss in a mineral.
 * //HARDNESS//:** the scratch resistance of various minerals through the ability of a harder material to scratch a softer material.

__Special properties:__ Minerals can be only identified absolutely by x-ray analysis and chemical tests. The x-ray analysis determines the structure of the mineral and the chemical tests determine the composition of the mineral. Structure and composition are the defining marks of a mineral. Unfortunately for the average collector, these tests require expensive equipment, expert know-how and often destroy the specimen. Fortunately, both structure and composition affect certain physical properties. It is through the proper use of these properties that minerals can reliably be identified. An idealized physical property is one that will give a unique result for each mineral and will always give the same result, again and again, for any and every specimen of that mineral. This is of course idealized. Mineralogists are usually happy to have a property that simply is consistent in providing the same result for every specimen of a certain mineral. Hopefully, this property also has a good range of possible results so that two similar minerals might stand a good chance of having different results. It would be nice if every mineral had their own special test that we could name after them such as the "**Fluorite Test**" for example. But they //usually// don't, so we must catalog all the results of several known physical property tests and hope that a collector can find enough positive (or diagnostically negative) results out of these to identify an unknown mineral.