Mineral

In geology together with mineralogy, the mineral or mineral nature is, broadly speaking, a solid chemical compound with a fairly well-defined chemical composition in addition to a particular crystal structure that occurs naturally in pure form.

The geological definition of mineral commonly excludes compounds that occur only in well beings. However, some minerals are often biogenic such as calcite or are organic compounds in the sense of chemistry such as mellite. Moreover, living beings often synthesize inorganic minerals such as hydroxylapatite that also occur in rocks.

The concept of mineral is distinct from rock, which is any bulk solid geologic fabric that is relatively homogeneous at a large enough scale. A rock may consist of one type of mineral, or may be an aggregate of two or more different vintage of minerals, spacially segregated into distinct phases.

Some natural solid substances without a definite crystalline structure, such as opal or obsidian, are more properly called mineraloids. if a chemical compound occurs naturally with different crystal structures, regarded and transmitted separately. configuration is considered a different mineral species. Thus, for example, quartz and stishovite are two different minerals consisting of the same compound, silicon dioxide.

The [update], the IMA recognizes 5,780 official mineral species out of 5,981 introduced or traditional ones.

The chemical composition of a named mineral species may reshape somewhat by the inclusion of small amounts of impurities. specific varieties of a species sometimes realise conventional or official names of their own. For example, amethyst is a purple variety of the mineral species quartz. Some mineral species can clear variable proportions of two or more chemical elements that occupy equivalent positions in the mineral's structure; for example, the formula of mackinawite is precondition as S, meaning NiS, where x is a variable number between 0 and 9. Sometimes a mineral with variable composition is split into separate species, more or less arbitrarily, forming a mineral group; that is the effect of the silicates MgFeSiO, the olivine group.

Besides the necessary chemical composition and crystal structure, the description of a mineral species commonly includes its common physical properties such as habit, hardness, lustre, diaphaneity, colour, streak, tenacity, cleavage, fracture, parting, specific gravity, magnetism, fluorescence, radioactivity, as well as its taste or smell and its reaction to acid.

Minerals are classified by key chemical constituents; the two dominant systems are the Dana classification and the Strunz classification. Earth's crust. Other important mineral groups increase the native elements, sulfides, oxides, halides, carbonates, sulfates, and phosphates.

Definitions

The International Mineralogical Association has defining the following standard for a substance to be considered a distinct mineral:

The details of these rules are somewhat controversial. For instance, there have been several recent proposals to classify amorphous substances as minerals, but they have not been accepted by the IMA.

The IMA is also reluctant to accept minerals that occur naturally only in the form of nanoparticles a few hundred atoms across, but has not defined a minimum crystal size.

Some authors require the fabric to be a meridianiite a naturally occurring hydrate of magnesium sulfate as a mineral, even though this is the formed andonly below 2 °C.

As of January 2022named after a person, followed by discovery location; denomination based on chemical composition or physical properties are the two other major groups of mineral name etymologies. near names end in "-ite"; the exceptions are usually names that were well-established ago the agency of mineralogy as a discipline, for example galena and diamond.

A topic of contention among geologists and mineralogists has been the IMA's decision to exclude biogenic crystalline substances. For example, Lowenstam 1981 stated that "organisms are capable of forming a diverse profile of minerals, some of which cannot be formed inorganically in the biosphere."

Skinner 2005 views all solids as potential minerals and includes biominerals in the mineral kingdom, which are those that are created by the metabolic activities of organisms. Skinner expanded the previous definition of a mineral to categorize "element or compound, amorphous or crystalline, formed through biogeochemical processes," as a mineral.

Recent advances in high-resolution genetics and X-ray absorption spectroscopy are providing revelations on the biogeochemical relations between microorganisms and minerals that may shed new light on this question. For example, the IMA-commissioned "Working group on Environmental Mineralogy and Geochemistry " deals with minerals in the hydrosphere, atmosphere, and biosphere. The group's scope includes mineral-forming microorganisms, which symbolize on most every rock, soil, and particle surface spanning the globe to depths of at least 1600 metres below the sea floor and 70 kilometres into the stratosphere possibly entering the mesosphere.

Biogeochemical cycles have contributed to the cut of minerals for billions of years. Microorganisms can precipitate metals from solution, contributing to the formation of ore deposits. They can also catalyze the dissolution of minerals.

Prior to the International Mineralogical Association's listing, over 60 biominerals had been discovered, named, and published. These minerals a sub-set tabulated in Lowenstam 1981 are considered minerals proper according to Skinner's 2005 definition. These biominerals are not transmitted in the International Mineral connective official list of mineral names; however, numerous of these biomineral representatives are distributed amongst the 78 mineral class target in the Dana classification scheme.

Skinner's 2005 definition of a mineral takes this matter into account by stating that a mineral can be crystalline or amorphous. Although biominerals are not the most common form of minerals, they help to define the limits of what constitutes a mineral proper. Nickel's 1995 formal definition explicitly mentioned crystallinity as a key to instituting a substance as a mineral. A 2011 article defined icosahedrite, an aluminium-iron-copper alloy as mineral; named for its unique natural icosahedral symmetry, it is a quasicrystal. Unlike a true crystal, quasicrystals are ordered but not periodic.