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The Mohs scale of mineral hardness, based on scratch hardness comparison, defines value 1 as the hardness of talc, the softest mineral. When scraped on a streak plate , talc produces a white streak, though this indicator is of little importance, because most silicate minerals produce a white streak.
In the context of nutrition, a mineral is a chemical element. Some "minerals" are essential for life, but most are not. [ 1 ] [ 2 ] [ 3 ] Minerals are one of the four groups of essential nutrients; the others are vitamins , essential fatty acids , and essential amino acids . [ 4 ]
Mineral classification schemes and their definitions are evolving to match recent advances in mineral science. Recent changes have included the addition of an organic class, in both the new Dana and the Strunz classification schemes. [152] [153] The organic class includes a very rare group of minerals with hydrocarbons. The IMA Commission on ...
This is a list of minerals which have Wikipedia articles.. Minerals are distinguished by various chemical and physical properties. Differences in chemical composition and crystal structure distinguish the various species.
Red ochre takes its reddish colour from the mineral hematite, which is an anhydrous iron oxide, and the main ingredient of rust. It was one of the earliest pigments used by man. Hand prints made by using red ochre have been found in the Pech Merle cave in Southern France. They date to between 16,000 and 25,000 BC.
Soil conditions produce uniform or gradual color changes, while reducing environments result in disrupted color flow with complex, mottled patterns and points of color concentration. Sometimes, a distinct change in color within a soil profile indicates a change in the soil parent material or mineral origin. [3]
Mineral evolution is a recent hypothesis that provides historical context to mineralogy. It postulates that mineralogy on planets and moons becomes increasingly complex as a result of changes in the physical, chemical and biological environment.
Mineralogy applies principles of chemistry, geology, physics and materials science to the study of minerals. Mineralogy [n 1] is a subject of geology specializing in the scientific study of the chemistry, crystal structure, and physical (including optical) properties of minerals and mineralized artifacts.