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Colemanite

Colemanite

Colemanite (Ca₂B₆O₁₁·5H₂O) is a borate mineral found in evaporite deposits. Colemanite is a secondary mineral that forms when borax is deposited, and then regularly covered with boron containing water. The boron remains after the water evaporates, and the boron and borax eventually form other minerals as for example Colemanite. It was named after William T. Coleman (1824-1893), owner of the mine where it was first found. Group: Borates, Hardness: 4.5, Specific gravity: 2.42, cleavage: perfect, Fracture: uneven-conchoidal, mineral may be white, yellow, or gray. Streak: white. Transparent-translucent, luster: vitreous. Forms in evaporative deposites. Soluble in hydrochloric acid. Fuses easily, breaks up, and colors a flame green. It is monoclinic. Crystals are short and prismatic. Category:Borate minerals

Borate

The borate ion is BO₃^3-. A borate is a compound of the borate ion with metallic elements. Boron found in nature is commonly as a borate mineral. Boron is also found combined with silicate to form complex borosilicate minerals such as the tourmalines. Borate exists in many forms. In acid conditions, as boric acid, H₃BO₃. In more basic conditions, it occurs as the dihydrogen borate ion, H₂BO₃^-; the hydrogen borate ion, HBO₃^2-; and finally borate ion, BO₃^3-. Borate can form many polymeric ions. Especially common is the tetraborate ion, B₄O₇^2-; also as the hydrogen tetraborate ion, HB₄O₇^-. It also occurs as triborate and pentaborate. The various metaborate ions have an empirical formula of BO₂^-, and form metaborate compounds. For the borate compounds, formation of complicated infinite anion structures is extensive, perhaps surpassed only by the silicates. Common borate salts include sodium metaborate, NaBO₂, and sodium tetraborate, Na₂B₄O₇. The latter also occurs naturally as the hydrous mineral borax, Na₂B₄O₇·10H₂O. Death Valley, California is noted for borate mining. The Atacama Desert in Chile also contains mineable borate concentrations. Various forms of borate are used as wood preservatives. Borate esters include trimethyl borate, B(OCH₃)₃, which is used as a precursor to boronic esters for Suzuki couplings.

External links

[http://www.hydridesolutions.com/pdf/Trimethylborate.pdf TriMethyl Borate as a precursor to boronic esters] Category:Oxoanions

Mineral

This article is about minerals in the geologic sense; for nutrient minerals see dietary mineral; for the band see Mineral (band). Minerals are natural compounds formed through geological processes. The term "mineral" encompasses not only the material's chemical composition but also the mineral structures. Minerals range in composition from pure elements and simple salts to very complex silicates with thousands of known forms (organic compounds are usually excluded). The study of minerals is called mineralogy. mineralogy]

Mineral definition and classification

To be classified as a "true" mineral, a substance must be a solid and have a crystal structure. It must also be an inorganic, naturally-occurring, homogenous substance with a defined chemical composition. The chemical composition may vary between end members of a mineral system. For example the plagioclase feldspars comprise a continuous series from sodium-rich albite (NaAlSi₃O₈) to calcium-rich anorthite (CaAl₂Si₂O₈) with four recognized intermediate compositions between. Mineral-like substances that don't strictly meet the definition are sometimes classified as mineraloids. Other natural-occurring substances are Nonminerals. Industrial minerals is a commercial term and refers to commercially valuable mined materials (see also Minerals and Rocks section below). A crystal structure is the orderly geometric spatial arrangement of atoms in the internal structure of a mineral. There are 14 basic lattice arrangements of atoms in three dimensions in the six crystal systems, and all crystal structures currently recognized fit in one of these 14 arrangements. This crystal structure is based on regular internal atomic or ionic arrangement that is often visible as the mineral form. Even when the mineral grains are too small to see or are irregularly shaped the crystal structure can be determined by x-ray analysis and/or optical microscopy. Chemistry and crystal structure define together a mineral. In fact, two or more minerals may have the same chemical composition, but differ in crystal structure (these are known as polymorphs). For example, pyrite and marcasite are both iron sulfide. Similarly, some minerals have different chemical compositions, but the same crystal structure: for example, halite (made from sodium and chlorine), galena (made from lead and sulfur) and periclase (made from magnesium and oxygen) all share the same cubic crystal structure. Crystal structure greatly influences a mineral's physical properties. For example, though diamond and graphite have the same composition (both are pure carbon), graphite is very soft, while diamond is the hardest of all known minerals. There are currently just over 4,000 known minerals, according to the International Mineralogical Association, which is responsible for the approval of and naming of new mineral species found in nature.

Minerals and rocks

A mineral is a naturally occurring, inorganic substance with a definite chemical composition and a crystalline structure. A rock is an aggregate of one or more minerals. (A rock may also include organic remains.) The specific minerals in a rock can vary a lot. Some minerals, like quartz, mica or feldspar are common, while others have been found in only one or two locations worldwide. Over half of the mineral species known are so rare that they have only been found in a handful of samples, and many are known from only one or two small grains. Commercially valuable minerals and rocks are refered to as industrial minerals.

Physical properties of minerals

Classifying minerals can range from simple to very difficult. A mineral can be identified by several physical properties, some of them being sufficient for full identification without equivocation. In other cases, minerals can only be classified by more complex chemical or X-ray diffraction analysis; these methods, however, can be costly, time-consuming, and even risk damaging the sample. Physical properties commonly used are :
- Crystal structure and habit: See the above discussion of crystal structure. A mineral may show good crystal habit or form, or it may be massive, granular or compact with only microscopically visible crystals.
- Hardness: the physical hardness of a mineral is usually measured according to the Mohs scale of mineral hardness.
- Luster indicates the way a mineral's surface interacts with light and can range from dull to glassy (vitreous).
- Color indicates the appearance of the mineral in reflected light or transmitted light for translucent minerals (i.e. what it looks like to the naked eye).
- Streak refers to the color of the powder a mineral leaves after rubbing it on an unglazed porcelain streak plate.
- Cleavage describes the way a mineral may come apart or cleave in different ways. In thin section, cleavage is visible as thin parallel lines across a mineral.
- Fracture describes how a mineral breaks when broken contrary to its natural cleavage planes.
- Specific gravity relates the mineral mass to the mass of an equal volume of water, namely the density of the material.
- Other properties: fluorescence (response to ultraviolet light), magnetism, radioactivity, tenacity (response to mechanical induced changes of shape or form), and reactivity to dilute acids.

Chemical properties of minerals

Minerals may be classified according to chemical composition. They are here categorized by anion group. The list below is in approximate order of their abundance in the Earth's crust. The list follows the Dana classification system.

Silicate class

The largest group of minerals by far are the silicates, which are composed largely of silicon and oxygen, with the addition of ions such as aluminium, magnesium, iron, and calcium. Some important rock-forming silicates include the feldspars, quartz, olivines, pyroxenes, amphiboles, garnets, and micas.

Carbonate class

The carbonate minerals consist of those minerals containing the anion (CO₃)^2- and include calcite and aragonite (both calcium carbonate), dolomite (magnesium/calcium carbonate) and siderite (iron carbonate). Carbonates are commonly deposited in marine settings when the shells of dead planktonic life settle and accumulate on the sea floor. Carbonates are also found in evaporitic settings (e.g. the Great Salt Lake, Utah) and also in karst regions, where the dissolution and reprecipitation of carbonates leads to the formation of caves, stalactites and stalagmites. The carbonate class also includes the nitrate and borate minerals.

Sulfate class

Sulfates all contain the sulfate anion, in the form SO₄^2-. Sulfates commonly form in evaporitic settings where highly saline waters slowly evaporate, allowing the formation of both sulfates and halides at the water-sediment interface. Sulfates also occur in hydrothermal vein systems as gangue minerals along with sulfide ore minerals. Another occurrence is as secondary oxidation products of original sulfide minerals. Common sulfates include anhydrite (calcium sulfate), celestite (strontium sulfate), barite (barium sulfate), and gypsum (hydrated calcium sulfate). The sulfate class also includes the chromate, molybdate, selenate, sulfite, tellurate, and tungstate minerals.

Halide class

The halides are the group of minerals forming the natural salts and include fluorite (calcium fluoride), halite (sodium chloride), sylvite (potassium chloride), and sal ammoniac (ammonium chloride). Halides, like sulfates, are commonly found in evaporitic settings such as playa lakes and landlocked seas such as the Dead Sea and Great Salt Lake. The halide class includes the fluoride, chloride, and iodide minerals.

Oxide class

Oxides are extremely important in mining as they form many of the ores from which valuable metals can be extracted. They commonly occur as precipitates close to the Earth's surface, oxidation products of other minerals in the near surface weathering zone, and as accessory minerals in igneous rocks of the crust and mantle. Common oxides include hematite (iron oxide), magnetite (iron oxide), chromite (chromium oxide), spinel (magnesium aluminium oxide - a common component of the mantle), rutile (titanium dioxide), and ice (hydrogen oxide). The oxide class includes the oxide and the hydroxide minerals.

Sulfide class

Many sulfides are economically important as metal ores. Common sulfides include pyrite (iron sulfide - commonly known as fools' gold), chalcopyrite (copper iron sulfide) and galena (lead sulfide). The sulfide class also includes the selenides, the tellurides, the arsenides, the antimonides, the bismuthinides, and the sulfosalts (sulfur and a second anion such as arsenic).

Phosphate class

The phosphate mineral group actually includes any mineral with a tetrahedral unit AO₄ where A can be phosphorus, antimony, arsenic or vanadium. By far the most common phosphate is apatite which is an important biological mineral found in teeth and bones of many animals. The phosphate class includes the phosphate, arsenate, vanadate, and antimonate minerals.

Element class

The Elemental group includes metals and intermetallic elements (gold, silver, copper), semi-metals and non-metals (antimony, bismuth, graphite, sulfur). This group also includes natural alloys, such as electrum (a natural alloy of gold and silver), phosphides, silicides, nitrides and carbides (which are usually only found naturally in a few rare meteorites).

External links

- [http://mineral.galleries.com/minerals/by_name.htm Mineral gallery]
- [http://www.minerals.net/index.htm Minerals.net]
- [http://www.mindat.org/index.php mindat.org mineral database]
- [http://webmineral.com Webmineral.com]
- [http://www.minerant.org/databases.html a directory of on-line databases related to mineralogy and crystallography]

References

- [http://volcanoes.usgs.gov/Products/Pglossary/mineral.html Photo glossary of volcano terms from the USGS Volcano Hazards Program] Category:Geology Category:Mineralogy
- ja:鉱物 simple:Mineral th:แร่

Boron

|- | colspan="6" align="center" |
- Boron-10 content may be as low as 19.1% and as
high as 20.3% in natural samples. Boron-11 is
the remainder in such cases. Boron is a chemical element in the periodic table that has the symbol B and atomic number 5. A trivalent metalloid element, boron occurs abundantly in the ore borax. There are two allotropes of boron; amorphous boron is a brown powder, but metallic boron is black. The metallic form is hard (9.3 on Mohs' scale) and a bad conductor in room temperatures. It is never found free in nature.

Notable characteristics

Boron is electron-deficient, possessing a vacant p-orbital. It is an electrophile. Compounds of boron often behave as Lewis acids, readily bonding with electron-rich substances in an attempt to quench boron's insatiable hunger for electrons. Optical characteristics of this element include the transmittance of infrared light. At standard temperatures boron is a poor electrical conductor but is a good conductor at high temperatures. Boron nitride can be used to make materials that are almost as hard as diamond. The nitride also acts as an electrical insulator but conducts heat similar to a metal. This element also has lubricating qualities that are similar to graphite. Boron is also similar to carbon with its capability to form stable covalently bonded molecular networks.

Applications

The most economically important compounds of boron are:
- sodium tetraborate pentahydrate Na₂B₄O₇ · 5H₂O, which is used in large amounts in making insulating fibreglass and sodium perborate bleach,
- orthoboric acid H₃BO₃ or boric acid, used in the production of textile fibreglass and flat panel displays or eye drops, among many uses, and
- sodium tetraborate decahydrate Na₂B₄O₇ · 10H₂O or borax, used in the production of adhesives, in anti-corrosion systems and many other uses. Of the several hundred uses of boron compounds, one can cite the following ones:
- Boron being an essential micronutrient, playing notably a role in plant fertilisation and in the building of cell wall structures, it is used in agriculture.
- Because of its distinctive green flame, amorphous boron is used in pyrotechnic flares.
- Boric acid is an important compound used in textile products.
- Boric acid is also traditionally used as an insecticide, notably against ants or cockroaches.
- Compounds of boron are used extensively in organic synthesis and in the manufacture of borosilicate and borophophosilicate glasses.
- Other compounds are used as wood preservatives, and are particularly attractive in this regard because they possess low toxicity.
- Boron-10 is used to assist control of nuclear reactors, a shield against radiation and in neutron detection.
- Purified boron-11 (depleted boron) is used for borosilicate glasses in rad-hard electronics.
- Research is being conducted into fusion power by interaction of hydrogen and boron. Potential benefits include relatively small and uncomplicated reactors and supposedly greater safety.
- Boron filaments are high-strength, lightweight materials that are chiefly used for advanced aerospace structures as a component of composite materials.
- Sodium borohydride (NaBH₄), is a popular chemical reducing agent, used (for example) for reducing aldehydes and ketones to alcohols.
- Boron in trace amounts is used as dopant for P-type semiconductors. Boron compounds are being investigated for use in a broad range of applications, including as components in sugar-permeable membranes, carbohydrate sensors and bioconjugates. Medicinal applications being investigated include boron neutron capture therapy and drug delivery. Other boron compounds show promise in treating arthritis. Hydrides of boron are oxidized easily and liberate a considerable amount of energy. They have therefore been studied for use as possible rocket fuels.

History

Compounds of boron (Arabic Buraq from Persian Burah) have been known of for thousands of years. In early Egypt, mummification depended upon an ore known as natron, which contained borates as well as some other common salts. Borax glazes were used in China from 300 AD, and boron compounds were used in glassmaking in ancient Rome. The element was not isolated until 1808 by Sir Humphry Davy, Joseph Louis Gay-Lussac, and Louis Jacques Thénard, to about 50 percent purity. These men did not recognize the substance as an element. It was Jöns Jakob Berzelius in 1824 who identified boron as an element. The first pure boron was produced by the American chemist W. Weintraub in 1909.

Occurrence

The United States and Turkey are the world's largest producers of boron. Boron does not appear in nature in elemental form but is found combined in borax, boric acid, colemanite, kernite, ulexite and borates. Boric acid is sometimes found in volcanic spring waters. Ulexite is a borate mineral that naturally has properties of fiber optics. Economically important sources are from the ore rasorite (kernite) and tincal (borax ore) which are both found in the Mojave Desert of California (with borax being the most important source there). Turkey is another place where extensive borax deposits are found. Pure elemental boron is not easy to prepare. The earliest methods used involve reduction of boric oxide with metals such as magnesium or aluminium. However the product is almost always contaminated with metal borides. (The reaction is quite spectacular though.) Pure boron can be prepared reducing volatile boron halogenides with hydrogen at high temperatures. In 1997 crystalline boron (99% pure) cost about US$5 per gram and amorphous boron cost about US$2 per gram.

Isotopes

Boron has two naturally-occurring and stable isotopes, ¹¹B (80.1%) and ¹⁰B (19.9%). The mass difference results in a wide range of δB-11 values in natural waters, ranging from -16 to +59. There are 13 known isotopes of boron, the shortest-lived isotope is ⁷B which decays through proton emission and alpha decay. It has a half-life of 3.26500x10^-22 s. Isotopic fractionation of boron is controlled by the exchange reactions of the boron species B(O H)₃ and B(OH)₄. Boron isotopes are also fractionated during mineral crystallization, during H₂O phase changes in hydrothermal systems, and during hydrothermal alteration of rock. The latter effect species preferential removal of the ¹⁰B(OH)₄ ion onto clays results in solutions enriched in ¹¹B(OH)₃ may be responsible for the large ¹¹B enrichment in seawater relative to both oceanic crust and continental crust; this difference may act as an isotopic signature.

Depleted boron

The Boron-10 isotope is good at capturing thermal neutrons from cosmic radiation or in PWRs (Pressurized Water Reactor, a type of nuclear power reactor). It then undergoes fission - producing a gamma ray, an alpha particle, and a lithium ion. When this happens inside of an integrated circuit, the fission products may then dump charge into nearby chip structures, causing data loss (bit flipping, or single event upset). In critical semiconductor designs, depleted boron - consisting almost entirely of Boron-11 - is used, to avoid this effect, as one of radiation hardening measures. Boron-11 is a by-product of the nuclear industry.

Precautions

Elemental boron and borates are not toxic and therefore do not require special precautions while handling. Some of the more exotic boron hydrogen compounds, however, are toxic and do require special handling care.

References

- [http://periodic.lanl.gov/elements/5.html Los Alamos National Laboratory – Boron]

External links

- [http://www.webelements.com/webelements/elements/text/B/index.html WebElements.com – Boron]
- [http://www.best-home-remedies.com/minerals/boron.htm Boron - Benefits, Deficiency Symptoms And Food Sources]
- [http://education.jlab.org/itselemental/ele005.html It's Elemental – Boron]
- [http://www.du.edu/~jcalvert/phys/boron.htm Boron]
- [http://www.inchem.org/documents/ehc/ehc/ehc204.htm Environmental Health Criteria 204: Boron (1998)] by the IPCS.
- [http://www.greenfacts.org/boron/index.htm A summary of the previous report] by GreenFacts.
- [http://www.compchemwiki.org/index.php?title=Boron Computational Chemistry Wiki]
- [http://theodoregray.com/PeriodicTable/Elements/005/ Boron - images and applications] Category:Chemical elements Category:Metalloids ko:붕소 ja:ホウ素 th:โบรอน

Boron

Notable characteristics

Applications

History

Occurrence

Isotopes

Depleted boron

Precautions

References

- [http://periodic.lanl.gov/elements/5.html Los Alamos National Laboratory – Boron]

External links

Borax

Borax, also called sodium borate or sodium tetraborate, is an important boron compound. It is a soft white many-sided crystal that dissolves easily in water. If left exposed to dry air, it slowly loses its water of hydration and become the white chalky mineral tincalconite (₂₄₇). Commercially sold borax is usually partially dehydrated. Borax occurs naturally in evaporite deposits produced by the repeated evaporation of seasonal lakes (see playa). The most commercially important deposits are found near Boron, California and other locations in the American southwest, the Atacama desert in Chile, and in Tibet. Borax may also be produced synthetically from other boron compounds. Tibet Borax is widely used in detergents, water softeners, soaps, disinfectants, and pesticides. One of its most widely advertised uses was as a hand-cleaner for industrial workers. It is used in making enamel glazes, glass and strengthening pottery and ceramics. It is also easily converted to boric acid or borate, which have many applications. Large amounts of borax are used for manufacturing insulating fibreglass and cellulose insulation as a fire retardant and anti-fungal compound. Large amounts are also used in production of sodium perborate monohydrate for use in detergents. A mixture of borax and ammonium chloride is used as a flux when welding iron and steel. It lowers the melting point of the unwanted iron oxide (scale), allowing it to run off. Borax is also used mixed with water as a flux when soldering jewelry metals such as gold or silver. It allows the molten solder to flow evenly over the joint in question. When used in a mixture, borax can be used to kill carpenter ants, and fleas. Borax is also an ingredient in Slime. The origin of the name is traceable to the Persian word bürah. The word was also used disparagingly in the 1940s to refer to tawdrily designed modernistic furniture and other works of industrial design. Some say that the use came from advertisement displays for the household clearer, though the use may also derive from the Yiddish word "borachs," meaning rented furniture. Borax is also a food additive in some countries (it is banned in the United States), with E number E285. Its use is similar to salt, and it appears notably in French and Iranian caviar. Such caviar plays a key part in the book "Murder at the British Embassy" by Margaret Truman.

External links

- [http://www.ilo.org/public/english/protection/safework/cis/products/icsc/dtasht/_icsc05/icsc0567.htm International Chemical Safety Card 0567]
- [http://www.ilo.org/public/english/protection/safework/cis/products/icsc/dtasht/_icsc12/icsc1229.htm International Chemical Safety Card 1229] (fused borax)
- [http://www.cdc.gov/niosh/npg/npgd0058.html NIOSH Pocket Guide to Chemical Hazards]
-
- Category:Sodium compounds Category:Borates Category:Borate minerals Category:Cleaning products Category:Cleaning product components Category:Household chemicals Category:Food additives ja:ホウ砂

1893

1893 was a common year starting on Sunday (see link for calendar).

Events

- January 1 - Japan accepts the Gregorian calendar
- January 2 - Introduction by Webb C. Ball of the General Railroad Timepiece Standards in North America: Railroad chronometers
- January 13 - The Independent Labour Party of the UK has its first meeting.
- January 17 - Intervention by the U.S. Marines in Hawaii, resulting in overthrow of government of Queen Liliuokalani of Hawaii
- January 21 - First "performance" of the Cherry sisters in Marion, Iowa. Their neighbors are uncritical and the sisters decide to launch a tour
- February 1 - Thomas A. Edison finishes construction of the first motion picture studio (West Orange, New Jersey).
- February 21 - Thomas Edison receives two U.S. patents. The first is for a "Cut Out for Incandescent Electric Lamps" and another for a "Stop Device" (No. 491,992-3). Also No. 492,150 for "Process of Coating Conductors for Incandescent Lamps."
- February 23 - Rudolf Diesel receives a patent for the diesel engine
- March 4 - End of term for President of the United States Benjamin Harrison. He is succeeded by Stephen Grover Cleveland.
- March 10 - Côte d'Ivoire becomes a French colony
- March 20 - In Belgium, Adam Worth is sentenced for seven year for robbery (he is released 1897)
- April 8 - First recorded college basketball game occurs in Beaver Falls, Pennsylvania between the Geneva College Covenanters and the New Brighton YMCA.
- May 1 - The 1893 World's Fair, also known as the World's Columbian Exposition, opens to the public in Chicago, Illinois, USA. The first United States commemorative postage stamps were issued for the Exposition.
- May 5 - Panic of 1893: Crash on the New York Stock Exchange starts a depression.
- May 9 - First public demonstration of Edison's 1 1/2" system of Kinetoscope at the Brooklyn Institute.
- June 6 - Marriage of Prince George, Duke of York and Mary of Teck.
- June 7 Gandhi's first act of civil disobedience.
- June 22 - Flagship Victoria of the British Mediterranean Fleet collides with Camperdown and sinks in 10 minutes - vice-admiral Sir George Tryon goes down with it
- July 6 - The small town of Pomeroy, Iowa was nearly destroyed by a tornado. Seventy-one people were killed and two hundred were injured.
- July 11 - Kokichi Mikimoto develops the method to achieve cultured pearls.
- July 12 - Frederick Jackson Turner gives his famous lecture entitled "The Significance of the Frontier in American History" before the American Historical Association in Chicago
- June 20 - Lizzie Borden acquitted of murder of her father and stepmother
- June 22 – Flagship HMS Victoria of the British Mediterranean Fleet collides with HMS Camperdown and sinks in 10 minutes - vice-admiral Sir George Tryon goes down with it
- August 27 - The Sea Islands Hurricane hits Savannah, Charleston and the Sea Islands; 1000-2000 dead.
- September 11 - Opening meeting of the World Parliament of Religions in Chicago.
- September 19 - Russian ironclad Rusalka disappears in a storm en route from Tallinn to Helsinki (hulk found July 2003 off Helsinki)
- September 27 - Closing meeting of the World Parliament of Religions in Chicago.
- October 10 - First car number plates in Paris, France
- October 30 - The 1893 World's Fair, also known as the World Columbian Exposition, closes.
- November 7 - Colorado women are granted the right to vote.

Exact month/day of event unknown

- New Zealand becomes first country in the world to grant women the vote.
- American Council on Alcohol Problems established.
- Global financial panic (Panic of 1893)
- Physicist Wilhelm Wien composes Wien's Law
- France conquers Vietnam.
- General strike in Belgium
- American Temperance University opened.
- Milbank Penitentiary in Britain demolished
- US President Cleveland operated on in secret
- The Wengernalpbahn in Wengen, Switzerland (Canton of Bern) is opened.
- Athletic Club Královské Vinohrady is founded. Later the team was renamed to Sparta Prague
- Anti-Saloon League established in U.S. to promote temperance movement
- Committee of Fifty for the Study of the Liquor Problem established.

Births

- January 5 - Paramahansa Yogananda, Indian guru (d. 1952)
- January 12 - Hermann Göring, Nazi official (d. 1946)
- January 12 - Alfred Rosenberg, Nazi official (d. 1946)
- January 15 - Ivor Novello, Welsh actor and musician (d. 1951)
- January 22 - Conrad Veidt, German actor (d. 1943)
- February 3 - Gaston Julia, French mathematician (d. 1978)
- February 10 - Jimmy Durante, American actor, singer, and comedian (d. 1980)
- February 12 - Omar Bradley, American general (d. 1981)
- February 16 - Katharine Cornell, American actress (d. 1974)
- February 21 - Andrés Segovia, Spanish guitarist (d. 1987)
- March 1 - Mercedes de Acosta, American poet, playwright, costume designer, and socialite (d. 1968)
- March 3 - Beatrice Wood, American artist and ceramicist (d. 1998)
- March 18 - Wilfred Owen, English soldier and poet (d. 1918)
- April 3 - Leslie Howard, English actor (d. 1943)
- April 9 - Victor Gollancz, British publisher (d. 1967)
- April 12 - Robert Harron, American actor (d. 1920)
- April 23 - Allen Dulles, American Central Intelligence Agency director (d. 1969)
- April 29 - Harold C. Urey, American chemist, Nobel Prize laureate (d. 1981)
- May 3 - Konstantine Gamsakhurdia, Georgian writer and public benefactor (d. 1975)
- May 23 - Ulysses S. Grant IV, American geologist and paleontologist (d. 1977)
- June 24 - Roy Oliver Disney, brother and business partner of Walter Elias Disney (d. 1971)
- July 25 - Dorothy Dickson, American-born actress and socialite (d. 1995)
- June 26 - Big Bill Broonzy, American blues singer and composer (d. 1958)
- July 3 - Mississippi John Hurt, American musician (d. 1966)
- July 9 - George Geary, English cricketer (d. 1981)
- August 6 - Wright Patman, American politician (d. 1976)
- August 15 - Leslie Comrie, New Zealand astronomer and computing pioneer (d. 1950)
- August 22 - Dorothy Parker, American writer (d. 1967)
- August 30 - Huey Long, Louisiana governor and senator (d. 1935)
- September 13 - Larry Shields, American musician (d. 1953)
- September 16 - Albert Szent-Györgyi, Hungarian physiologist, Nobel Prize laureate (d. 1986)
- October 1 - Marianne Brandt, German industrial designer (d. 1983)
- October 9 - Mário de Andrade, Brazilian writer and photographer (d. 1945)
- October 14 - Lillian Gish, American actress (d. 1993)
- October 15 - King Carol II of Romania (d. 1953)
- October 18 - Georges Ohsawa, Japanese founder of Macrobiotics (d. 1966)
- November 3 - Edward Adelbert Doisy, American biochemist, recipient of the Nobel Prize in Physiology or Medicine (d. 1986)
- November 8 - Clarence Williams, American jazz musician (d. 1965)
- December 24 - Ruth Chatterton, American actress (d. 1961)
- December 26 - Mao Zedong, Chinese leader (d. 1976)

Exact month/day of birth unknown

- Clement Martyn Doke, South African linguist (d. 1980)
- Berthold Bartosch, Bohemian animator (d. 1968)

Deaths

- January 2 - John Obadiah Westwood, British entomologist
- January 7 - Jožef Stefan, Slovenian physicist, mathematician, and poet (b. 1835)
- January 17 - Rutherford B. Hayes, 19th President of the United States
- January 23 - Lucius Quintus Cincinnatus Lamar, U.S. Supreme Court justice
- February 1 - George Henry Sanderson, Mayor of San Francisco
- February 20 - P.G.T. Beauregard, American Confederate general
- March 30 - Jane Sym-Mackenzie, First Lady of Canada
- June 21 - Amasa Leland Stanford, Governor of California
- June 23 - Sir Theophilus Shepstone, South African statesman (b. 1817)
- October 10 - Lip Pike, baseball player
- October 30 - Sir John Joseph Caldwell Abbott, Canadian politician

Marriages

- January 7 - Mary Gish & James Leigh de Guiche
- April 20 - King Ferdinand & Maria Louisa de Bourbon
- May 2 - Marie Eve & August Strindberg
- May 30 - Israël Querido & Janet Sjouwerman
- July 6 - George V & Queen Mary
- December 12 - Rupert Hughes & Agnes Wheeler Hedge Category:1893 ko:1893년 ms:1893 simple:1893 th:พ.ศ. 2436

Category:Borate minerals

The borate minerals contain the borate anion, BO₃^3-. Category:Minerals

Caelum (constellation)

Caelum (Latin for chisel, and similar to Latin for of the Sky) is a minor southern constellation introduced by Nicolas Louis de Lacaille.

Table of leading stars

History

Since this is a southern constellation, invented in the 17th century, there is no pre 17th-century mythology associated with it.

Stars

:Stars with Bayer designations: :
- α Cae 4.45; β Cae 5.05; γ Cae – double 4.55 & 6.34; δ Cae 4.55; ζ Cae 6.35; λ Cae 6.24; ν Cae 6.06

External links

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Hans Fiebrandt
Hans Fiebrandt (
- 16. August 1905 in Berlin; † 10. Februar 2001 in Berlin-Wilmersdorf) war ein deutscher Schauspieler. Hans Fiebrandt wurde als 10. und letztes Kind eines Werkmeisters in Berlin geboren und wuchs im Elternhaus an der Holzmarktstraße nähe

Colemanite

Borate

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Mineral

Mineral definition and classification

Minerals and rocks

Physical properties of minerals

Chemical properties of minerals

Silicate class

Carbonate class

Sulfate class

Halide class

Oxide class

Sulfide class

Phosphate class

Element class

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References

Boron

Notable characteristics

Applications

History

Occurrence

Isotopes

Depleted boron

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Boron

Notable characteristics

Applications

History

Occurrence

Isotopes

Depleted boron

Precautions

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References

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Borax

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1893

Events

Exact month/day of event unknown

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Exact month/day of birth unknown

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Category:Borate minerals

Caelum (constellation)

Table of leading stars

History

Stars

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