Biotite is a common phyllosilicate mineral within the mica group, with the approximate chemical formula K(Mg, Fe)3AlSi3O10(F, OH)2. The silicate minerals make up the largest and most important class of rock-forming Minerals They are classified based on the structure of their silicate Ion group A mineral is a naturally occurring substance formed through geological processes that has a characteristic chemical composition a highly ordered atomic structure and specific The word "mica" is thought to be derived from the Latin word la micare, "glitteren" in reference to the brilliant appearance of this mineral (especially More generally, it refers to the dark mica series, primarily a solid-solution series between the iron-endmember annite, and the magnesium-endmember phlogopite; more aluminous endmembers include siderophyllite. Phlogopite is a yellow greenish or reddish-brown member of the Mica family of phyllosilicates. Siderophyllite is a rare member of the Mica group of Silicate minerals with formula KFe++Al(Al2Si2O10(FOH2
Biotite is a sheet silicate. For the Artificial intelligence Androids of the 1990s Science fiction series Space Above and Beyond, see Silicate (AI Iron, magnesium, aluminium, silicon, oxygen, and hydrogen form sheets that are weakly bond together by potassium ions. It is sometimes called "iron mica" because it is more iron-rich than phlogopite. It is also sometimes called "black mica" as opposed to "white mica" (muscovite) -- both form in some rocks, in some instances side-by-side. Muscovite (also known as Common Mica, Isinglass, or Potash mica) is a phyllosilicate Mineral of Aluminium
Like other mica minerals, biotite has a highly perfect basal cleavage, and consists of flexible sheets, or lamellae, which easily flake off. The word "mica" is thought to be derived from the Latin word la micare, "glitteren" in reference to the brilliant appearance of this mineral (especially A lamella is a Gill -shaped structure fine sheets of material held adjacent one another with fluid in-between-(or simply 'welded'-plates It has a monoclinic crystal system, with tabular to prismatic crystals with an obvious pinacoid termination. In Crystallography, the monoclinic Crystal system is one of the 7 lattice Point groups A crystal system is described by three vectors. It has four prism faces and two pinacoid faces to form a pseudohexagonal crystal. Although not easily seen because of the cleavage and sheets, fracture is uneven. It has a hardness of 2. The Mohs scale of mineral hardness characterizes the scratch resistance of various Minerals through the ability of a harder material to scratch a softer material 5 - 3, a specific gravity of 2. Specific gravity is defined as the ratio of the Density of a given solid or liquid substance to the density of water at a specific temperature and pressure typically 7 - 3. 1, and an average density of 3. 09 g/cm³. It appears greenish to brown or black, and even yellow when weathered. Green is a Color, the perception of which is evoked by light having a spectrum dominated by energy with a Wavelength of roughly 520–570- nm. Black, when used as a general term is a color that is a Very dark Black, black, or Black, of low Luminance relative to Black is the Color of objects that do not emit or Reflect Light in any part of the Visible spectrum; they absorb all such frequencies of Yellow is the Color evoked by light that stimulates both the L and M (long and medium wavelength Cone cells of the Retina about equally It can be transparent to opaque, has a vitreous to pearly lustre, and a grey-white streak. In its weathered yellow, sparkly form, it is a common type of “fool’s Gold” (Pyrite is the official “fool’s Gold”). When biotite is found in large chunks, they are called “books” because it resembles a book with pages of many sheets.
Biotite is found in a wide variety of igneous rocks and metamorphic rocks. Igneous rocks (etymology from Latin ignis, fire are rocks formed by solidification of cooled Magma (molten rock Metamorphic rock is the result of the transformation of an existing rock type the protolith, in a process called Metamorphism, which means "change For instance, biotite occurs in the lava of Mount Vesuvius and at Monzoni. Lava is molten rock expelled by a Volcano during an eruption When first expelled from a volcanic vent it is a Liquid at Temperatures Mount Vesuvius (in Italian Monte Vesuvio and in Latin Mons Vesuvius) is an active Stratovolcano east of Naples It is an essential phenocryst in some varieties of lamprophyre. A phenocryst is a relatively large and usually conspicuous Crystal distinctly larger than the grains of the rock groundmass of a Porphyritic Igneous Lamprophyres ( Greek λαµπρός (lamprós = "bright" and φύρω (phýro = to mix are uncommon small volume ultrapotassic Igneous rocks Biotite is occasionally found in large sheets, especially in pegmatite veins, as in New England, Virginia and North Carolina. Pegmatite is a very coarse-grained Igneous rock that has a grain size of 20 mm or more such rocks are referred to as pegmatitic. History See also History of New England New England's earliest inhabitants were Algonquian -speaking Native Americans including the The Commonwealth of Virginia ( is an American state North Carolina ( is a state located on the Atlantic Seaboard in the southeastern United States Other notable occurrences include Bancroft and Sudbury, Ontario. Bancroft ( 2006 Population 3838 is a Town located on the York River in Hastings County Greater Sudbury (2006 Census population 157857 is a city in Northern Ontario, Canada. Ontario (ɒnˈtɛrioʊ is a province located in the central part of Canada, the largest by population and second largest after Quebec It is an essential constituent of many metamorphic schists, and it forms in suitable compositions over a wide range of pressure and temperature. The schists form a group of medium-grade Metamorphic rocks chiefly notable for the preponderance of lamellar Minerals such as Micas chlorite
It is not industrially useful, but it is mined using quarrying and underground mining (depending on the depth of the biotite) for collection purposes.
Biotite is used extensively to constrain ages of rocks, by either potassium-argon dating or argon-argon dating. Potassium-argon dating or K-Ar dating is a Radiometric dating method used in Geochronology and Archeology. Because argon escapes readily from the biotite crystal structure at high temperatures, these methods may provide only minimum ages for many rocks. Biotite is also useful in assessing temperature histories of metamorphic rocks, because the partitioning of iron and magnesium between biotite and garnet is sensitive to temperature. Iron (ˈаɪɚn is a Chemical element with the symbol Fe (ferrum and Atomic number 26 Magnesium (mægˈniːziəm is a Chemical element with the symbol Mg, Atomic number 12 Atomic weight 24 The garnet group includes a group of minerals that have been used since the Bronze Age as gemstones and abrasives
Biotite was named by J.F.L. Hausmann in 1847 in honour of the French physicist Jean-Baptiste Biot, who, in 1816, researched the optical properties of mica, discovering many unique properties. A dielectric is a nonconducting substance ie an insulator. The term was coined by William Whewell in response to a request from Michael Faraday. A capacitor is a passive electrical component that can store Energy in the Electric field between a pair of conductors This article is about the electronic device not an evacuated pipe used for experiments in Free-fall. Johann Friedrich Ludwig Hausmann ( February 22, 1782 - December 26, 1859) German Mineralogist, was born in Hanover This article is about the country For a topic outline on this subject see List of basic France topics. A physicist is a Scientist who studies or practices Physics. Physicists study a wide range of physical phenomena in many branches of physics spanning Jean-Baptiste Biot (21 April 1774 Paris &ndash 3 February 1862 Paris) was a French Physicist, Astronomer and Mathematician
"The Mineral Biotite". This is a List of Minerals for which there are Wikipedia articles 1995,1996 Amethyst Gallery Inc. 
"Biotite Mineral Data". 
"BIOTITE". LoveToKnow 1911 Online Encyclopedia. 2003, 2004 LoveToKnow.