The 8 Main Groups That Make Up The Mineral Kingdom

 When you think of minerals, it might be difficult to imagine what they are. Many people think of gems when they imagine a mineral. It turns out there’s a lot more to minerals than just gemstones. In fact, there are at least eight different classifications of minerals, and I’m going to tell you about each one. It has been said that there are as many ways to classify a mineral as there are mineralogists. Regardless of how they are classified, minerals can usually be grouped together by their chemical composition or by the way their atoms are arranged.


different types of minerals

Minerals are divided into eight major groups: silicates, oxides, sulfates, carbonates, halides, native elements, sulfides, and phosphates. They each have different crystal structures and chemical compositions to which they can be identified. Silicates are the most common group of minerals. Silicate minerals make up most of the crust and mantle of the Earth (over 90% by volume). 

Silicate

Silicate minerals are made up of silicon and oxygen. These two elements account for over 90% of the Earth’s crust, so silicates make up the bulk of our rocks. There are many different kinds of silicate minerals, but they all contain silicon and oxygen. the silicate group of minerals is further divided into the following classes: Some examples are quartz (SiO2), feldspar (KAlSi3O8), mica (K2Al4Si3O10(OH)2), amphibole (NaFe+2(Mg, Fe+3)5Si8O22(OH)2), and olivine ((Mg, Fe)2SiO4).

quartz crystals

Sulfides

Sulfides. These minerals consist of a metal atom bonded to sulfur or to another metal atom with a charge like iron (II). Pyrite is an example of a common sulfide mineral. Sulfides tend to be heavy and often have an earthy luster. Minerals from this group frequently form interesting crystal shapes such as cubes and octahedrons. Pyrite is often called "fool's gold" because it has a yellowish color like gold, but it does not have the same value as gold. Sulfides have sulfur in them instead of oxygen. Some sulfide minerals include galena, sphalerite, bornite, and pyrite. Galena is a lead sulfide used for making lead batteries and solder. Sphalerite is a zinc sulfide used for making brass and as an ore for zinc production. Bornite is a copper sulfide used for its copper content as an ore for copper production. 

Galena is a lead sulfide


Carbonates

Carbonates. These minerals are made up of a metal bonded to carbonate (CO32-), which has three oxygen atoms bonded to one carbon atom. Calcite is an example of a common carbonate mineral that can be found in limestone and marble formations along with Malachite as an ore mineral for copper.

Malachite ore Mineral

Oxide

Oxide minerals are composed of one or more metallic elements combined with oxygen. Many oxides are combinations of cations from the transition metals and oxygen anions (O2-), but some contain hydrogen and/or carbon as well (for example, water [H2O] is an oxide). Oxides can be inorganic or organic (containing carbon). Oxides make up about 4% of all minerals. Oxides include minerals that contain one or more oxygen atoms, such as Hematite (Fe2O3) and Magnetite (Fe3O4).

Hematite (Fe2O3)

Halides

These include minerals in which the metal is combined with halogen elements like chlorine, fluorine, or iodine. Halide minerals tend to be soft, light, and soluble in water. Halides are minerals that have halide anions that carry a negative 1 charge. These include fluorite or CaF2 (calcium fluoride), cryolite or Na3AlF6 (sodium hexafluoroaluminate), and halite or NaCl (sodium chloride). 

Fluorite Mineral

Sulfates

Sulfates are minerals with sulfate anions that carry a negative 2 charge. The chemical formula for sulfates is M2(SO4)3, where "M" is any metallic element. Some examples of sulfate minerals include gypsum or CaSO4·2H2O (calcium sulfate dihydrate), barite or BaSO4 (barium sulfate), and anhydrite or CaSO4 (calcium sulfate). 

Gypsum Mineral

Native Elements

Gold is a native element. It is one of the few highly polished precious metals that can be found in nature. Other native elements include silver and copper. Carbon is another example of a native element mineral; it is the only nonmetal that qualifies as a native element. Diamonds too are pure carbon, but their crystalline structure makes them hard substances used mostly for decorative purposes. Diamonds form under high temperature and pressure conditions that exist only about 100 miles beneath the earth’s surface.

Native Gold

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phosphate

The phosphate group of minerals includes a variety of species with high economic significance. The two most economically important are apatite and monazite. Apatite is the defining mineral for 5 on the Mohs scale, and monazite is an important source of rare earth metals. Apatite is a group of phosphate minerals, usually referring to hydroxylapatite, fluorapatite, and chlorapatite, [Ca5(PO4)3(OH, F, Cl)] with high concentrations of OH−, F− and Cl− ions, respectively, in the crystal. The formula for fluorapatite is written as Ca10(PO4)6F2, and chlorapatite is written as Ca10(PO4)6Cl2. Apatites are relatively hard (5 on the Mohs scale), they have a vitreous luster and are transparent to translucent with colors ranging from brownish green to yellow or blue depending on composition.

Apatite-(CaF)-Calcite

Conclusion.

In that respect, while they are formal classifications, these groups are also informal in the sense that their names have not been standardized and there is much variation in usage. For example, a very large proportion of minerals are ungrouped. There also is controversy regarding the very nature of the classification system itself: Is it a rigid order or a flexible framework? It should be noted that these group names are not used in most mineral identification tests and will not appear on the labels from commercially sourced materials. There may be multiple reasons for this oversight but perhaps the main reason is simply convenience mode the allocation of a mineral to one of the eight groups satisfies regulatory requirements and therefore does not need more detailed classification Information on each of these groups.

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