Minerals comprise essential entities for organisms that are required as nutrients. These abiogenic substances occur naturally in usually various crystalline forms and have a definite chemical composition along with some distinct physical and chemical properties.
What are Minerals?
Minerals are formed of either the same elements or are present in combination with others. The majority of mineral-forming compounds are comprised of more than just 1 element. Therefore, as pure elements are also considered as chemical substances, not all substances are compounds while all compounds are substances.
Similarly, all minerals are considered as substances but not all these substances are considered as minerals. However, allotropes of an element may also be considered minerals and can even be referred to as pure elements. Pure elements exist in an uncombined state but have a characteristic structure.
Some examples of pure minerals include gold, iron, silver, copper, platinum, and iron. The multiple substances comprised by only 1 kind of element differing only in their structure are known as allotropes. For example, carbon allotropes include coal, diamonds, and graphite all of which are formed of carbon.
A mineral is naturally occurring and is often formed by a geologic phenomenon and not artificially made like synthetic diamonds. For instance, diamond is an example of the hardest mineral ever known. Minerals are not formed as the result of living organisms’ activity or processes and thus are abiogenic.
For example, Pearls are natural gemstones but not regarded as a true mineral as they occur due to biological processes by shelled mollusks within their mantle. A natural pearl is comprised mainly of layers of nacre and sometimes calcite.
Nacre is a composite material consisting of calcium carbonate and conchiolin protein. Therefore, a pearl cannot be regarded as a material itself even though it is made of substances categorized as minerals (aragonite and calcite). This also applies other substances like bone, amber, shells, tooth, oxalate crystals, urinary calculi, and other hard fossilized remains.
Mineral sediments can replace decayed body constituents in a fossil and these types of fossils can be considered minerals. As minerals are produced by geologic processes they are referred to as inorganic, as they are not the result of biological activity. Nevertheless, it does not mean that minerals do not comprise organic carbon.
In the Nickel-Strunz classification system, there is a class of minerals that consists of organic minerals as they are of geologic origin. Minerals occur in crystalline form as their atoms show a recurring orderly pattern over regular intervals. A chemical formula can be utilized to represent the. Minerals can be distinguished as they have distinctive physical properties like cleavage, density, hardness, and luster.
Minerals are solid at room temperature and are stable with the exception of mineral water that occurs in a liquid state at room temperature but crystallizes below 0 °C to form ice.
Biological Importance of Minerals
Many minerals serve as a source of nutrients and are essential for organisms. In respect to nutrients, mineral pertains to any inorganic element that can serve as a dietary source and is vital to nutrition. They form one of the four groups of vital nutrients; the other groups include essential amino acids, vitamins, and essential fatty acids.
The essential elements in the case of humans include macrominerals, bulk elements, and trace elements. The bulk elements are carbon, oxygen, hydrogen, sulfur, and nitrogen that comprise the majority of the diet. The recommended consumption of these bulk elements is 10 grams/day. The macrominerals are required in relatively lower quantities.
Examples include calcium, potassium, phosphorus, sodium, magnesium, and chlorine. These nutrients form an essential part of biological compounds like RNA and DNA and provide key ions. A trace element is required in only small quantities but is essential for different biological processes.
Examples include iron, zinc, silicon, copper, rubidium, strontium, tin, bromine, iodine, manganese, lead aluminum, and barium. Iron is a trace element that forms a vital component of pigment hemoglobin that occurs in RBCs of vertebrates. It is the iron component that binds and transports oxygen in respiratory organs.
The process of formation of a biomineral is known as Biomineralization. A biomineral does not belong to the category of true minerals as it is formed by biological activity or processes for providing structural or mechanical support.
Biominerals include carbonates, calcium phosphate, silicates, and iron and gold deposits produced by certain bacteria. Mineralized tissues are tissues that comprise biominerals. Examples include bones, tooth enamel, cartilages, shells of mollusks, dentin, and diatoms.
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