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  2. Mineral - Wikipedia

    en.wikipedia.org/wiki/Mineral

    The basic level of definition is that of mineral species, each of which is distinguished from the others by unique chemical and physical properties. For example, quartz is defined by its formula , SiO 2 , and a specific crystalline structure that distinguishes it from other minerals with the same chemical formula (termed polymorphs ).

  3. Portal:Minerals - Wikipedia

    en.wikipedia.org/wiki/Portal:Minerals

    It is a black granular form of corundum, in which the mineral is intimately mixed with magnetite, hematite, or hercynite. In addition to its hardness, corundum has a density of 4.02 g/cm 3 (251 lb/cu ft), which is unusually high for a transparent mineral composed of the low- atomic mass elements aluminium and oxygen .

  4. Mineralogy - Wikipedia

    en.wikipedia.org/wiki/Mineralogy

    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. Specific studies within mineralogy ...

  5. Crystal - Wikipedia

    en.wikipedia.org/wiki/Crystal

    A crystallographic form is described by placing the Miller indices of one of its faces within brackets. For example, the octahedral form is written as {111}, and the other faces in the form are implied by the symmetry of the crystal. Forms may be closed, meaning that the form can completely enclose a volume of space, or open, meaning that it ...

  6. Rock (geology) - Wikipedia

    en.wikipedia.org/wiki/Rock_(geology)

    The proportion of silica in rocks and minerals is a major factor in determining their names and properties. [7] Rock outcrop along a mountain creek near Orosí, Costa Rica. Rocks are classified according to characteristics such as mineral and chemical composition, permeability, texture of the constituent particles, and particle size.

  7. Quartz - Wikipedia

    en.wikipedia.org/wiki/Quartz

    Quartz is a hard, crystalline mineral composed of silica (silicon dioxide).The atoms are linked in a continuous framework of SiO 4 silicon–oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical formula of SiO 2.

  8. Clay mineral - Wikipedia

    en.wikipedia.org/wiki/Clay_mineral

    In 2013, analytical tests by the Curiosity rover found results consistent with the presence of smectite clay minerals on the planet Mars. [22] [23] [24] Illite group which includes the clay-micas. Illite is the only common mineral in this group. [21] Chlorite group includes a wide variety of similar minerals with considerable chemical variation ...

  9. Chert - Wikipedia

    en.wikipedia.org/wiki/Chert

    Chert (/ tʃ ɜːr t /) is a hard, fine-grained sedimentary rock composed of microcrystalline or cryptocrystalline quartz, [1] the mineral form of silicon dioxide (SiO 2). [2] Chert is characteristically of biological origin, but may also occur inorganically as a chemical precipitate or a diagenetic replacement, as in petrified wood.