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Macle
Macle is a term used in crystallography. It is a crystalline form, twin-crystal or double crystal (such as chiastolite). It is crystallographic twin according to the spinel twin law and is seen in octahedral crystals or minerals such as diamond and spinel. The twin law name comes from the fact that is commonly observed in the mineral spinel. A version with five units about a common axis is called a fiveling. ''Macle'' is an old French word, a heraldic term for a voided Lozenge (shape)">lozenge (one diamond Diamond is a Allotropes of carbon, solid form of the element carbon with its atoms arranged in a crystal structure called diamond cubic. Diamond is tasteless, odourless, strong, brittle solid, colourless in pure form, a poor conductor of e ... shape within another). Etymologically the word is derived from the Latin ''macula'' meaning spot, mesh, or hole. Bibliography * Georges Friedel (1904) "Étude sur les groupements cristallins", ''Extrait du Bulletin de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Diamond
Diamond is a Allotropes of carbon, solid form of the element carbon with its atoms arranged in a crystal structure called diamond cubic. Diamond is tasteless, odourless, strong, brittle solid, colourless in pure form, a poor conductor of electricity, and insoluble in water. Another solid form of carbon known as graphite is the Chemical stability, chemically stable form of carbon at Standard temperature and pressure, room temperature and pressure, but diamond is metastable and converts to it at a negligible rate under those conditions. Diamond has the highest Scratch hardness, hardness and thermal conductivity of any natural material, properties that are used in major industrial applications such as cutting and polishing tools. Because the arrangement of atoms in diamond is extremely rigid, few types of impurity can contaminate it (two exceptions are boron and nitrogen). Small numbers of lattice defect, defects or impurities (about one per million of lattice atoms) can color ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Fiveling
A fiveling, also known as a decahedral nanoparticle, a multiply-twinned particle (MTP), a pentagonal nanoparticle, a pentatwin, or a five-fold twin is a type of twinned crystal that can exist at sizes ranging from nanometers to millimetres. It contains five different single crystals arranged around a common axis. In most cases each unit has a Cubic crystal system#Bravais lattice, face centered cubic (fcc) arrangement of the atoms, although they are also known for other types of crystal structure. They nucleate at quite small sizes in the nanometer range, but can be grown much larger. They have been found in mineral crystals excavated from mines such as pentagonite or native gold from Ukraine, in rods of metals grown via electrochemical processes and in nanoparticles produced by the condensation of metals either onto substrates or in inert gases. They have been investigated for their potential uses in areas such as improving the efficiency of solar cell or heterogeneous catalysis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Crystal Twinning
Crystal twinning occurs when two or more adjacent crystals of the same mineral are oriented so that they share some of the same crystal lattice points in a symmetrical manner. The result is an intergrowth of two separate crystals that are tightly bonded to each other. The surface along which the lattice points are shared in twinned crystals is called a composition surface or twin plane. Crystallographers classify twinned crystals by a number of twin laws, which are specific to the crystal structure. The type of twinning can be a diagnostic tool in mineral identification. There are three main types of twinning. The first is growth twinning which can occur both in very large and very small particles. The second is transformation twinning, where there is a change in the crystal structure. The third is deformation twinning, in which twinning develops in a crystal in response to a shear stress, and is an important mechanism for permanent shape changes in a crystal. Definition T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Georges Friedel
Georges Friedel (19 July 1865 – 11 December 1933) was a French mineralogist and crystallographer. Life Georges was the son of the chemist Charles Friedel. Georges' grandfather was Louis Georges Duvernoy who held the chair in comparative anatomy from 1850 to 1855 at the Muséum national d'histoire naturelle. Georges studied at the École Polytechnique in Paris and the École Nationale des Mines in St. Etienne, and was a student of François Ernest Mallard. In 1893 he obtained a professorship at the École Nationale des Mines, of which he would later become the director. After the First World War, he returned as a professor to the University of Strasbourg in Alsace. Due to ill health, he took early retirement in 1930, and died in 1933. He was married with five children. Scientific works Like his teacher Mallard, Friedel concerned himself with the theories of Auguste Bravais, the founder of crystallography. Friedel was able to demonstrate the theoretical ideas of Brav ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Heraldry
Heraldry is a discipline relating to the design, display and study of armorial bearings (known as armory), as well as related disciplines, such as vexillology, together with the study of ceremony, Imperial, royal and noble ranks, rank and genealogy, pedigree. Armory, the best-known branch of heraldry, concerns the design and transmission of the Achievement (heraldry), heraldic achievement. The achievement, or armorial bearings usually includes a coat of arms on a escutcheon (heraldry), shield, helmet (heraldry), helmet and Crest (heraldry), crest, together with any accompanying devices, such as supporters, Heraldic badge, badges, Heraldic flag, heraldic banners and mottoes. Although the use of various devices to signify individuals and groups goes back to Ancient history, antiquity, both the form and use of such devices varied widely, as the concept of regular, hereditary designs, constituting the distinguishing feature of heraldry, did not develop until the High Middle Ages. It i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Bulletin De La Société De L'Industrie Minérale
Bulletin or The Bulletin may refer to: Periodicals (newspapers, magazines, journals) * ''Bulletin'' (online newspaper), a Swedish online newspaper * ''The Bulletin'' (Australian periodical), an Australian magazine (1880–2008) ** Bulletin Debate, a famous dispute from 1892 to 1893 between Henry Lawson and Banjo Paterson * ''The Bulletin'' (alternative weekly), an alternative weekly published in Montgomery County, Texas, U.S. * ''The Bulletin'' (Bend), a daily newspaper in Bend, Oregon, U.S. * ''The Bulletin'' (Belgian magazine), a weekly English-language magazine published in Brussels, Belgium * ''The Bulletin'' (Philadelphia newspaper), a newspaper in Philadelphia, Pennsylvania, U.S. (2004–2009) * ''The Bulletin'' (Norwich) * ''London Bulletin'', surrealist monthly magazine (1938–1940) * ''The Morning Bulletin'', a daily newspaper published in Rockhampton, Queensland, Australia since 1861 * ''Philadelphia Bulletin'', a newspaper published in Philadelphia, U.S. (1847� ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Merriam-Webster
Merriam-Webster, Incorporated is an list of companies of the United States by state, American company that publishes reference work, reference books and is mostly known for Webster's Dictionary, its dictionaries. It is the oldest dictionary publisher in the United States. In 1831, George Merriam, George and Charles Merriam founded the company as G & C Merriam Co. in Springfield, Massachusetts. In 1843, after Noah Webster died, the company bought the rights to ''Webster's Dictionary#Noah Webster's American Dictionary of the English Language, An American Dictionary of the English Language'' from Webster's estate. All Merriam-Webster dictionaries trace their lineage to this source. In 1964, Encyclopædia Britannica, Inc., acquired Merriam-Webster, Inc., as a subsidiary. The company adopted its current name, Merriam-Webster, Incorporated, in 1982. History 19th century In 1806, Webster published his first dictionary, s:A Compendious Dictionary of the English Language, ''A Compen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Mesh
Medical Subject Headings (MeSH) is a comprehensive controlled vocabulary for the purpose of indexing journal articles and books in the life sciences. It serves as a thesaurus of index terms that facilitates searching. Created and updated by the United States National Library of Medicine (NLM), it is used by the MEDLINE/PubMed article database and by NLM's catalog of book holdings. MeSH is also used by ClinicalTrials.gov registry to classify which diseases are studied by trials registered in ClinicalTrials. MeSH was introduced in the 1960s, with the NLM's own index catalogue and the subject headings of the Quarterly Cumulative Index Medicus (1940 edition) as precursors. The yearly printed version of MeSH was discontinued in 2007; MeSH is now available only online. It can be browsed and downloaded free of charge through PubMed. Originally in English, MeSH has been translated into numerous other languages and allows retrieval of documents from different origins. Structure MeSH ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Latin
Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area around Rome, Italy. Through the expansion of the Roman Republic, it became the dominant language in the Italian Peninsula and subsequently throughout the Roman Empire. It has greatly influenced many languages, Latin influence in English, including English, having contributed List of Latin words with English derivatives, many words to the English lexicon, particularly after the Christianity in Anglo-Saxon England, Christianization of the Anglo-Saxons and the Norman Conquest. Latin Root (linguistics), roots appear frequently in the technical vocabulary used by fields such as theology, List of Latin and Greek words commonly used in systematic names, the sciences, List of medical roots, suffixes and prefixes, medicine, and List of Latin legal terms ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Lozenge (shape)
A lozenge ( ; symbol: ), often referred to as a diamond, is a form of rhombus. The definition of ''lozenge'' is not strictly fixed, and the word is sometimes used simply as a synonym () for ''rhombus''. Most often, though, lozenge refers to a thin rhombus—a rhombus with two acute and two obtuse angles, especially one with acute angles of 45°. The lozenge shape is often used in parquetry (with acute angles that are 360°/''n'' with ''n'' being an integer higher than 4, because they can be used to form a set of tiles of the same shape and size, reusable to cover the plane in various geometric patterns as the result of a tiling process called tessellation in mathematics) and as decorative art, decoration on ceramics (art), ceramics, Silver (household), silverware and textiles. It also features in heraldry and Suit (cards), playing cards. Symbolism The lozenge motif dates from the Neolithic and Paleolithic art, Paleolithic period in Eastern Europe and represents a sown Field (agr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Pyrite 60608
The mineral pyrite ( ), or iron pyrite, also known as fool's gold, is an iron sulfide with the chemical formula Fe S2 (iron (II) disulfide). Pyrite is the most abundant sulfide mineral. Pyrite's metallic luster and pale brass-yellow hue give it a superficial resemblance to gold, hence the well-known nickname of ''fool's gold''. The color has also led to the nicknames ''brass'', ''brazzle'', and ''brazil'', primarily used to refer to pyrite found in coal. The name ''pyrite'' is derived from the Greek (), 'stone or mineral which strikes fire', in turn from (), 'fire'. In ancient Roman times, this name was applied to several types of stone that would create sparks when struck against steel; Pliny the Elder described one of them as being brassy, almost certainly a reference to what is now called pyrite. By Georgius Agricola's time, , the term had become a generic term for all of the sulfide minerals. Pyrite is usually found associated with other sulfides or oxides in qua ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
