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61-514: Haüy can refer to several people: René Just Haüy (1743–1822), French mineralogist, brother of Valentin Haüy Valentin Haüy (1745–1822), French founder of the first school for the blind Topics referred to by the same term [REDACTED] This disambiguation page lists articles associated with the title Haüy . If an internal link led you here, you may wish to change

122-436: A dissolution and reprecipitation mechanism, with the reaction rate controlled by the surface area of a calcite crystal. The second stage of the reaction is approximately 10 times slower. However, crystallization of calcite has been observed to be dependent on the starting pH and concentration of magnesium in solution. A neutral starting pH during mixing promotes the direct transformation of ACC into calcite without

183-531: A goniometer , and looking for the smallest numbers that fit. Later, a "structural" unit cell was determined using X-ray crystallography . The morphological unit cell is rhombohedral , having approximate dimensions a = 10 Å and c = 8.5 Å , while the structural unit cell is hexagonal (i.e. a rhombic prism ), having approximate dimensions a = 5 Å and c = 17 Å . For the same orientation, c must be multiplied by 4 to convert from morphological to structural units. As an example, calcite cleavage

244-527: A specific gravity of 2.71 and, in crystalline varieties, a vitreous luster . Color is white or none, though shades of gray, red, orange, yellow, green, blue, violet, brown, or even black can occur when the mineral is charged with impurities. Calcite has numerous habits, representing combinations of over 1000 crystallographic forms . Most common are scalenohedra , with faces in the hexagonal {2 1 1} directions (morphological unit cell) or {2 1 4} directions (structural unit cell); and rhombohedral, with faces in

305-692: A classic in the field. By then, Haüy had applied his ideas to the differentiation of different species. He systematically described all the known minerals, sorting them into classes, and giving their chemical and geometrical properties. His work, in four volumes, including an atlas of plates, was accounted among the most wonderful of the 19th century. It has been described as "a work of comprehensive insight, and much of it, written with literary fluency". A second updated edition appeared as Traité de cristallographie in 1822. Haüy created comprehensive collections containing hundreds of pear-wood models of crystal models for education and demonstrations. One such set

366-611: A clear piece of calcite to appear doubled. The birefringent effect (using calcite) was first described by the Danish scientist Rasmus Bartholin in 1669. At a wavelength of about 590 nm, calcite has ordinary and extraordinary refractive indices of 1.658 and 1.486, respectively. Between 190 and 1700 nm, the ordinary refractive index varies roughly between 1.9 and 1.5, while the extraordinary refractive index varies between 1.6 and 1.4. Calcite has thermoluminescent properties mainly due to manganese divalent ( Mn ). An experiment

427-699: A collection of all Earth materials. In October 1794, René Just Haüy was appointed the first curator of the Cabinet of Mineralogy, later known as the Musée de Minéralogie . He may therefore be considered a founder of the Musée de Minéralogie. On November 9, 1794, Haüy also became a professor of physics at the École normale supérieure . In 1802, Haüy became a professor of mineralogy at the Muséum national d'Histoire naturelle (National Museum of Natural History). Haüy's work

488-467: A group this enlightened amateur was showing me, and which formed part of his mineralogical collection. The prism had a single fracture along one of the edges of the base, by which it had been attached to the rest of the group. Instead of placing it in the collection I was then forming, I tried to divide it in other directions, and I succeeded, after several attempts, in extracting its rhomboid nucleus." René-Just Haüy, Traité de minéralogie (1801) Studying

549-570: A lecture by Louis-Jean-Marie Daubenton , in mineralogy . His brother Valentin Haüy was the founder of the first school for the blind, the Institution des Jeunes Aveugles (Institute for Blind Youth) in Paris. An accident apparently directed René-Just Haüy's attention to what became a new field in natural history , crystallography . Haüy was examining a broken specimen of calcareous spar in

610-405: A monohydrocalcite intermediate, sequestering carbon . Calcite is often the primary constituent of the shells of marine organisms , such as plankton (such as coccoliths and planktic foraminifera ), the hard parts of red algae , some sponges , brachiopods , echinoderms , some serpulids , most bryozoa , and parts of the shells of some bivalves (such as oysters and rudists ). Calcite

671-449: A similar-looking, translucent variety of fine-grained banded deposit of calcite. In publications, two different sets of Miller indices are used to describe directions in hexagonal and rhombohedral crystals, including calcite crystals: three Miller indices h, k, l in the a 1 , a 2 , c {\displaystyle a_{1},a_{2},c} directions, or four Bravais–Miller indices h, k, i, l in

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732-526: A vaterite intermediate. But when ACC forms in a solution with a basic initial pH, the transformation to calcite occurs via metastable vaterite, following the pathway outlined above. Magnesium has a noteworthy effect on both the stability of ACC and its transformation to crystalline CaCO 3 , resulting in the formation of calcite directly from ACC, as this ion destabilizes the structure of vaterite. Epitaxial overgrowths of calcite precipitated on weathered cleavage surfaces have morphologies that vary with

793-546: Is derived from the German Calcit , a term from the 19th century that came from the Latin word for lime , calx (genitive calcis ) with the suffix -ite used to name minerals. It is thus a doublet of the word chalk . When applied by archaeologists and stone trade professionals, the term alabaster is used not just as in geology and mineralogy, where it is reserved for a variety of gypsum ; but also for

854-441: Is designed to promote sustainable development in the mining industry. Calcite can help synthesize precipitated calcium carbonate (PCC) (mainly used in the paper industry) and increase carbonation . Furthermore, due to its particular crystal habit, such as rhombohedron, hexagonal prism, etc., it promotes the production of PCC with specific shapes and particle sizes. Calcite, obtained from an 80 kg sample of Carrara marble ,

915-437: Is divided into low-magnesium and high-magnesium calcite, with the dividing line placed at a composition of 4% magnesium. High-magnesium calcite retains the calcite mineral structure, which is distinct from that of dolomite , MgCa(CO 3 ) 2 . Calcite can also contain small quantities of iron and manganese . Manganese may be responsible for the fluorescence of impure calcite, as may traces of organic compounds. Calcite

976-767: Is found all over the world, and its leading global distribution is as follows: Calcite is found in many different areas in the United States. One of the best examples is the Calcite Quarry in Michigan. The Calcite Quarry is the largest carbonate mine in the world and has been in use for more than 85 years. Large quantities of calcite can be mined from these sizeable open pit mines. Calcite can also be found throughout Canada, such as in Thorold Quarry and Madawaska Mine, Ontario, Canada. Abundant calcite

1037-467: Is found in spectacular form in the Snowy River Cave of New Mexico as mentioned above, where microorganisms are credited with natural formations. Trilobites , which became extinct a quarter billion years ago , had unique compound eyes that used clear calcite crystals to form the lenses. It also forms a substantial part of birds' eggshells, and the δ C of the diet is reflected in the δ C of

1098-407: Is given as "perfect on {1 0 1 1}" in morphological coordinates and "perfect on {1 0 1 4}" in structural units. In { h k l } {\displaystyle \{hkl\}} indices, these are {1 0 1} and {1 0 4}, respectively. Twinning , cleavage and crystal forms are often given in morphological units. The diagnostic properties of calcite include a defining Mohs hardness of 3,

1159-775: Is mined in the Santa Eulalia mining district, Chihuahua, Mexico. Large quantities of calcite in Iceland are concentrated in the Helgustadir mine . The mine was once the primary mining location of "Iceland spar." However, it currently serves as a nature reserve, and calcite mining will not be allowed. Calcite is found in parts of England, such as Alston Moor, Egremont, and Frizington, Cumbria. St. Andreasberg, Harz Mountains, and Freiberg, Saxony can find calcite. Ancient Egyptians carved many items out of calcite, relating it to their goddess Bast , whose name contributed to

1220-554: Is one of the minerals that has been shown to catalyze an important biological reaction, the formose reaction , and may have had a role in the origin of life. Interaction of its chiral surfaces (see Form ) with aspartic acid molecules results in a slight bias in chirality; this is one possible mechanism for the origin of homochirality in living cells. Climate change is exacerbating ocean acidification , possibly leading to lower natural calcite production. The oceans absorb large amounts of CO 2 from fossil fuel emissions into

1281-403: Is the leading cause of excessive growth of cyanobacteria. As an active capping material, calcite can help reduce P release from sediments into the water, thus inhibiting cyanobacteria overgrowth. Calcite is a common constituent of sedimentary rocks , limestone in particular, much of which is formed from the shells of dead marine organisms. Approximately 10% of sedimentary rock is limestone. It

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1342-480: Is the primary mineral in metamorphic marble . It also occurs in deposits from hot springs as a vein mineral; in caverns as stalactites and stalagmites ; and in volcanic or mantle-derived rocks such as carbonatites , kimberlites , or rarely in peridotites . Cacti contain Ca-oxalate biominerals. Their death releases these biominerals into the environment, which subsequently transform to calcite via

1403-590: Is used as the IAEA -603 isotopic standard in mass spectrometry for the calibration of δ O and δ C . Calcite can be formed naturally or synthesized. However, artificial calcite is the preferred material to be used as a scaffold in bone tissue engineering due to its controllable and repeatable properties. Calcite can be used to alleviate water pollution caused by the excessive growth of cyanobacteria . Lakes and rivers can lead to cyanobacteria blooms due to eutrophication , which pollutes water resources. Phosphorus (P)

1464-531: Is used for optical purposes. Acute scalenohedral crystals are sometimes referred to as "dogtooth spar" while the rhombohedral form is sometimes referred to as "nailhead spar". The rhombohedral form may also have been the " sunstone " whose use by Viking navigators is mentioned in the Icelandic Sagas . Single calcite crystals display an optical property called birefringence (double refraction). This strong birefringence causes objects viewed through

1525-471: The a 1 , a 2 , a 3 , c {\displaystyle a_{1},a_{2},a_{3},c} directions, where i {\displaystyle i} is redundant but useful in visualizing permutation symmetries . To add to the complications, there are also two definitions of unit cell for calcite. One, an older "morphological" unit cell, was inferred by measuring angles between faces of crystals, typically with

1586-703: The French Revolution , Haüy refused to take an oath accepting the Civil Constitution of the Clergy , and became a non-juring priest . He was thrown into prison after the monarchy was overthrown on August 10, 1792. Étienne Geoffroy Saint-Hilaire interceded on his behalf. Haüy was released just a few days before the September Massacres of September 2–7, 1792 in which many of the clergy were killed. On August 8, 1793, in spite of

1647-515: The Légion d'Honneur . After 1814 Haüy was deprived of his appointments by the Restoration government. He spent his final days in poverty, dying in Paris on June 1, 1822, even if "June 3" is systematically reported. The confusion in Haüy's death date (June 1 instead of June 3) is an 1823 error by Cuvier , rectified in 1944 by A. Lacroix but still often misreported. In 1817, René-Just Haüy

1708-498: The National Convention passed a decree, in favor of developing uniform weights and measures across France. On September 11, 1793, they established a Temporary Commission of Weights and Measures made up of twelve scientists, including Haüy, whose task was to carry out the decree. The work of the commission was disrupted by political events. In November 1793, Lavoisier and several others were arrested and removed from

1769-510: The province of Picardy (later the département of Oise ). His parents were Just Haüy, a poor linen-weaver, and his wife Magdeleine Candelot. Haüy's interest in the services and music of the local church brought him to the attention of the prior of a nearby abbey of Premonstrants . Through him, Haüy was introduced to a colleague in Paris and obtained a scholarship to the College of Navarre . Haüy eventually became an usher, and in 1764,

1830-520: The Commission. On May 8, 1794, Lavoisier was guillotined. Nonetheless, Haüy remained secretary of the Commission through this turmoil. The law of 18 Germinal an III was enacted on April 7, 1795, formally establishing the metric system in France. On July 12, 1794, a public decree reorganized the École des Mines (School of Mines) in Paris and specified the establishment of a Cabinet of Mineralogy,

1891-580: The Royal Society's catalogue, to various scientific journals, especially the Journal de physique and the Annales du Museum d'Histoire Naturelle . Calcareous spar Other polymorphs of calcium carbonate are the minerals aragonite and vaterite . Aragonite will change to calcite over timescales of days or less at temperatures exceeding 300 °C, and vaterite is even less stable. Calcite

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1952-690: The calcite of the shell. The largest documented single crystal of calcite originated from Iceland, measured 7 m × 7 m × 2 m (23 ft × 23 ft × 6.6 ft) and 6 m × 6 m × 3 m (20 ft × 20 ft × 9.8 ft) and weighed about 250 tons. Classic samples have been produced at Madawaska Mine , near Bancroft, Ontario . Bedding parallel veins of fibrous calcite, often referred to in quarrying parlance as beef , occur in dark organic rich mudstones and shales, these veins are formed by increasing fluid pressure during diagenesis . Calcite formation can proceed by several pathways, from

2013-475: The classical terrace ledge kink model to the crystallization of poorly ordered precursor phases like amorphous calcium carbonate (ACC) via an Ostwald ripening process, or via the agglomeration of nanocrystals. The crystallization of ACC can occur in two stages. First, the ACC nanoparticles rapidly dehydrate and crystallize to form individual particles of vaterite . Second, the vaterite transforms to calcite via

2074-440: The collection of Jacques de France de Croisset. (According to some accounts, Haüy dropped the specimen and caused it to break.) He became intrigued by the perfectly smooth plane of the fracture. "The observation I have just noted is that which has served to develop my ideas on the structure of crystals. It presented itself in the case of a crystal that the citizen Defrance was kind enough to give me just after it had broken off from

2135-457: The development of X-Ray diffraction technology many years later, in 1902. Haüy was not the only researcher to observe that calcite crystals could be composed of smaller rhombohedra, but it was he who introduced the idea of triple periodicity in crystals. This idea was fundamental to later developments in the field on crystal lattices . Between 1784 and 1822, Haüy published more than 100 reports discussing his theories and their application to

2196-629: The efforts of Antoine Lavoisier , the Académie royale des sciences de Paris was dissolved by the National Convention . It was not restored until August 22, 1795, when it became known as the Institut National des Sciences et des Arts (National Institute of Sciences and Arts). Before its suppression, the Academy of Sciences had formed a working group to develop a uniform system of weights and measures for use throughout France. Lavoisier

2257-437: The expansion and eventual collapse of cave systems, resulting in various forms of karst topography . Calcite exhibits an unusual characteristic called retrograde solubility: it is less soluble in water as the temperature increases. Calcite is also more soluble at higher pressures. Pure calcite has the composition CaCO 3 . However, the calcite in limestone often contains a few percent of magnesium . Calcite in limestone

2318-484: The following reaction The carbon dioxide released by this reaction produces a characteristic effervescence when a calcite sample is treated with an acid. Due to its acidity, carbon dioxide has a slight solubilizing effect on calcite. The overall reaction is If the amount of dissolved carbon dioxide drops, the reaction reverses to precipitate calcite. As a result, calcite can be either dissolved by groundwater or precipitated by groundwater, depending on such factors as

2379-718: The fragments inspired Haüy to make further experiments in crystal cutting. Breaking down crystals to the smallest pieces possible, Haüy concluded that each type of crystal has a fundamental primitive, nucleus or “integrant molecule” of a particular shape, that could not be broken further without destroying both the physical and chemical nature of the crystal. He further argued that crystal structures are made up of orderly arrangements of these integrant molecules in successive layers, according to geometrical laws of crystallization . Crystals that had been classed together previously were identified as being of separate mineral species if their fundamental structure differed. Heavyspar, for example,

2440-732: The glow curve peaks, it was found that Pb and Mn acted as activators in the calcite lattice, but Pb was much less efficient than Mn . Measuring mineral thermoluminescence experiments usually use x-rays or gamma-rays to activate the sample and record the changes in glowing curves at a temperature of 700–7500 K. Mineral thermoluminescence can form various glow curves of crystals under different conditions, such as temperature changes, because impurity ions or other crystal defects present in minerals supply luminescence centers and trapping levels. Observing these curve changes also can help infer geological correlation and age determination. Calcite, like most carbonates, dissolves in acids by

2501-479: The link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=Haüy&oldid=541274783 " Category : Disambiguation pages Hidden categories: Short description is different from Wikidata All article disambiguation pages All disambiguation pages Ren%C3%A9 Just Ha%C3%BCy René Just Haüy ( French pronunciation: [aɥi] ) FRS MWS FRSE (28 February 1743 – 1 June 1822)

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2562-427: The ocean at the time they became mineralised, and retained this mineralogy for the remainder of their evolutionary history. Petrographic evidence for these calcite sea conditions consists of calcitic ooids , lmc cements, hardgrounds , and rapid early seafloor aragonite dissolution. The evolution of marine organisms with calcium carbonate shells may have been affected by the calcite and aragonite sea cycle. Calcite

2623-526: The primary inorganic precipitate of calcium carbonate in marine waters was low-magnesium calcite (lmc), as opposed to the aragonite and high-magnesium calcite (hmc) precipitated today. Calcite seas alternated with aragonite seas over the Phanerozoic , being most prominent in the Ordovician and Jurassic periods. Lineages evolved to use whichever morph of calcium carbonate was favourable in

2684-446: The rhombohedron form. Its fracture is conchoidal , but difficult to obtain. Scalenohedral faces are chiral and come in pairs with mirror-image symmetry; their growth can be influenced by interaction with chiral biomolecules such as L- and D- amino acids . Rhombohedral faces are not chiral. Calcite is transparent to opaque and may occasionally show phosphorescence or fluorescence . A transparent variety called " Iceland spar "

2745-433: The sky through the crystal and then rotating it so that the two images are of equal brightness, the rings of polarized light that surround the sun can be seen even under overcast skies. Identifying the sun's location would give seafarers a reference point for navigating on their lengthy sea voyages. In World War II, high-grade optical calcite was used for gun sights, specifically in bomb sights and anti-aircraft weaponry. It

2806-523: The structure of crystalline substances. Haüy first stated his laws of decrement in Essai d'une théorie sur la structure des crystaux (1784). It was a radical departure from his previous works, introducing his theory of molé constituantes or constituent molecules. By 1792, he had identified a number of parallelepipeds as possible primitive crystal forms. Haüy worked out the mathematical theory of his work in his Traité de minéralogie (1801), which became

2867-553: The subsurface in response to microorganism activity, such as sulfate -dependent anaerobic oxidation of methane , where methane is oxidized and sulfate is reduced , leading to precipitation of calcite and pyrite from the produced bicarbonate and sulfide . These processes can be traced by the specific carbon isotope composition of the calcites, which are extremely depleted in the C isotope, by as much as −125 per mil PDB (δ C). Calcite seas existed in Earth's history when

2928-417: The term alabaster because of the close association. Many other cultures have used the material for similar carved objects and applications. A transparent variety of calcite known as Iceland spar may have been used by Vikings for navigating on cloudy days. A very pure crystal of calcite can split a beam of sunlight into dual images, as the polarized light deviates slightly from the main beam. By observing

2989-457: The type of weathering the substrate experienced: growth on physically weathered surfaces has a shingled morphology due to Volmer-Weber growth, growth on chemically weathered surfaces has characteristics of Stranski-Krastanov growth, and growth on pristine cleavage surfaces has characteristics of Frank - van der Merwe growth. These differences are apparently due to the influence of surface roughness on layer coalescence dynamics. Calcite may form in

3050-495: The water temperature, pH , and dissolved ion concentrations. When conditions are right for precipitation, calcite forms mineral coatings that cement rock grains together and can fill fractures. When conditions are right for dissolution, the removal of calcite can dramatically increase the porosity and permeability of the rock, and if it continues for a long period of time, may result in the formation of caves . Continued dissolution of calcium carbonate-rich formations can lead to

3111-405: The {1 0 1} or {1 0 4} directions (the most common cleavage plane). Habits include acute to obtuse rhombohedra, tabular habits, prisms , or various scalenohedra . Calcite exhibits several twinning types that add to the observed habits. It may occur as fibrous, granular, lamellar, or compact. A fibrous, efflorescent habit is known as lublinite . Cleavage is usually in three directions parallel to

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3172-508: Was a French priest and mineralogist , commonly styled the Abbé Haüy after he was made an honorary canon of Notre Dame . Due to his innovative work on crystal structure and his four-volume Traité de Minéralogie (1801), he is often referred to as the "Father of Modern Crystallography". During the French Revolution he also helped to establish the metric system . René-Just Haüy was born at Saint-Just-en-Chaussée on February 28, 1743, in

3233-471: Was a major proponent, and on March 30, 1791, he submitted a plan on behalf of the Commission on Weights and Measures, which was adopted by the Constituent Assembly . Lavoisier and Haüy were tasked with determining the density of water. As of January 4, 1793, they determined the weight of a cubic decimeter of distilled water at the temperature of melting ice, the kilogram . On August 1, 1793,

3294-587: Was acquired by Martin van Marum , curator of the Teylers Museum and a director of the Hollandsche Maatschappij der Wetenschappen . Haüy is also known for his observations on pyroelectricity . He detected pyroelectricity in calamine , an oxide of zinc , as early as 1785. He studied pyroelectricity in a number of other minerals including tourmaline and related them to crystalline structure. He showed that electricity in tourmaline

3355-571: Was appointed regent (master) of the fourth class. Haüy also progressed in his religious training. He was tonsured in 1762, took minor orders in 1765, was appointed a subdeacon in 1767, became a deacon in 1769, and was ordained as a Roman Catholic priest in 1770. After his ordination, Haüy became regent (teacher) of the second class at the Collège du Cardinal-Lemoine. Through his friendship with his spiritual director, Abbé Lhomond , Haüy became interested first in botany , and after hearing

3416-591: Was appreciated by Napoleon , who made Haüy an Honorary Canon of the Eglise Métropolitain de Paris ( Notre Dame ) on April 5, 1802. On November 28, 1803, Haüy became one of the first recipients of the Order of the Légion d'Honneur . Napoleon encouraged Haüy to write Traité élémentaire de physique (1803), and is reported to have read it during his incarceration on Elba in 1814. During his brief return to power in 1815, Napoleon promoted Haüy to officer of

3477-426: Was conducted by adding activators such as ions of Mn, Fe, Co, Ni, Cu, Zn, Ag, Pb, and Bi to the calcite samples to observe whether they emitted heat or light. The results showed that adding ions ( Cu , Cu , Zn , Ag , Bi , Fe , Fe , Co , Ni ) did not react. However, a reaction occurred when both manganese and lead ions were present in calcite. By changing the temperature and observing

3538-430: Was differentiated into specimens containing barium and strontium . The value of Haüy's discovery was immediately recognized. Haüy and his contemporaries worked with limited evidence. They could observe a crystal's habit and cleavage planes and measure interfacial angles with an instrument called a goniometer . The internal structure underlying the crystal's integrant molecule would not be determinable until

3599-553: Was elected an honorary member of the New York Academy of Sciences . His name is the thirteenth inscribed on the south-east side of the Eiffel Tower . The mineral Haüyne was named for Haüy in 1807 by Thomas-Christophe Bruun-Neergaard. It occurs in silica-deficient igneous rocks in a wide variety of locations. The following are Haüy's principal works: He also contributed papers, of which 100 are enumerated in

3660-540: Was strongest at the poles of the crystal and became imperceptible at the middle. Haüy published a book on electricity and magnetism, Exposition raisonné de la théorie de l'électricité et du magnétisme, d'après les principes d'Æpinus , in 1787. On February 12, 1783, Haüy was elected to the Académie royale des sciences de Paris ( French Academy of Sciences ) with the rank of an adjoint in botany, there being no vacancy in either physics or mineralogy. In 1788, he became as an associate in natural history and mineralogy. During

3721-459: Was used as a polarizer (in Nicol prisms ) before the invention of Polaroid plates and still finds use in optical instruments. Also, experiments have been conducted to use calcite for a cloak of invisibility . Microbiologically precipitated calcite has a wide range of applications, such as soil remediation, soil stabilization and concrete repair. It also can be used for tailings management and

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