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Pearl
A pearl is a hard, glistening object produced within the soft tissue (specifically the mantle) of a living shelled mollusk or another animal, such as fossil conulariids. Just like the shell of a mollusk, a pearl is composed of calcium carbonate (mainly aragonite or a mixture of aragonite and calcite) in minute crystalline form, which has deposited in concentric layers. The ideal pearl is perfectly round and smooth, but many other shapes, known as baroque pearls, can occur. The finest quality of natural pearls have been highly valued as gemstones and objects of beauty for many centuries. Because of this, ''pearl'' has become a metaphor for something rare, fine, admirable and valuable. The most valuable pearls occur spontaneously in the wild, but are extremely rare. These wild pearls are referred to as ''natural'' pearls. ''Cultured'' or ''farmed'' pearls from pearl oysters and freshwater mussels make up the majority of those currently sold. Imitation pearls are also widely so ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbonate Mineral
Carbonate minerals are those minerals containing the carbonate ion, . Carbonate divisions Anhydrous carbonates *Calcite group: trigonal **Calcite CaCO3 **Gaspéite (Ni,Mg,Fe2+)CO3 **Magnesite MgCO3 **Otavite CdCO3 **Rhodochrosite MnCO3 **Siderite FeCO3 **Smithsonite ZnCO3 **Spherocobaltite CoCO3 *Aragonite group: orthorhombic **Aragonite CaCO3 **Cerussite PbCO3 **Strontianite SrCO3 **Witherite BaCO3 **Rutherfordine UO2CO3 **Natrite Na2CO3 Anhydrous carbonates with compound formulas *Dolomite group: trigonal **Ankerite CaFe(CO3)2 **Dolomite (mineral), Dolomite CaMg(CO3)2 **Huntite Mg3Ca(CO3)4 **Minrecordite CaZn(CO3)2 **Barytocalcite BaCa(CO3)2 Carbonates with hydroxyl or halogen *Carbonate with hydroxide: monoclinic **Azurite Cu3(CO3)2(OH)2 **Hydrocerussite Pb3(CO3)2(OH)2 **Malachite Cu2CO3(OH)2 **Rosasite (Cu,Zn)2CO3(OH)2 **Phosgenite Pb2(CO3)Cl2 **Hydrozincite Zn5(CO3)2(OH)6 **Aurichalcite (Zn,Cu)5(CO3)2(OH)6 Hydrated carbonates *Hydromagnesite Mg5(CO3)4(OH)2.4H2O *Ikaite ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metaphor
A metaphor is a figure of speech that, for rhetorical effect, directly refers to one thing by mentioning another. It may provide (or obscure) clarity or identify hidden similarities between two different ideas. Metaphors are often compared with other types of figurative language, such as antithesis, hyperbole, metonymy, and simile. One of the most commonly cited examples of a metaphor in English literature comes from the "All the world's a stage" monologue from '' As You Like It'': All the world's a stage, And all the men and women merely players; They have their exits and their entrances And one man in his time plays many parts, His Acts being seven ages. At first, the infant... :—William Shakespeare, '' As You Like It'', 2/7 This quotation expresses a metaphor because the world is not literally a stage, and most humans are not literally actors and actresses playing roles. By asserting that the world is a stage, Shakespeare uses points of comparison between the world an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Old Persian
Old Persian is one of the two directly attested Old Iranian languages (the other being Avestan language, Avestan) and is the ancestor of Middle Persian (the language of Sasanian Empire). Like other Old Iranian languages, it was known to its native speakers as (Iranian).''cf.'' , p. 2. Old Persian appears primarily in the inscriptions, clay tablets and seal (device), seals of the Achaemenid dynasty, Achaemenid era (c. 600 BCE to 300 BCE). Examples of Old Persian have been found in what is now Iran, Romania (Gherla), Armenia, Bahrain, Iraq, Turkey and Egypt, with the most important attestation by far being the contents of the Behistun Inscription (dated to 525 BCE). Recent research (2007) into the vast Persepolis Fortification Archive at the Oriental Institute at the University of Chicago unearthed Old Persian tablets, which suggest Old Persian was a written language in use for practical recording and not only for royal display. Origin and overview As a written language, Old ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Margaritiferidae
Margaritiferidae is a family of medium-sized freshwater mussels, aquatic bivalve molluscs in the order Unionida. Text may have been copied from this source, which is available under Attribution 4.0 International (CC BY 4.0)licence. It is the most threatened of all unionid families. The family is sometimes referred to as the freshwater pearl mussel family, but "freshwater pearl mussel" more often applies to the species ''Margaritifera margaritifera''. The name refers to the thick layer of nacre (mother of pearl) lining the interior of the shell of the species, which enables them to produce pearls. Taxonomy A 2018 study suggested a new phylogeny and systematics of the Margaritiferidae, comprising two subfamilies, Gibbosulinae and Margaritiferinae, and four genera, ''Gibbosula'', ''Cumberlandia'', ''Margaritifera'', and ''Pseudunio''. This family has ancient origins, having diverged from the ancestors of the Unionidae during the Late Triassic with the crown group of the Marga ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bivalve
Bivalvia (), in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class of marine and freshwater molluscs that have laterally compressed bodies enclosed by a shell consisting of two hinged parts. As a group, bivalves have no head and they lack some usual molluscan organs, like the radula and the odontophore. They include the clams, oysters, cockles, mussels, scallops, and numerous other families that live in saltwater, as well as a number of families that live in freshwater. The majority are filter feeders. The gills have evolved into ctenidia, specialised organs for feeding and breathing. Most bivalves bury themselves in sediment, where they are relatively safe from predation. Others lie on the sea floor or attach themselves to rocks or other hard surfaces. Some bivalves, such as the scallops and file shells, can swim. The shipworms bore into wood, clay, or stone and live inside these substances. The shell of a bivalve is composed of calc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perna (bivalve)
''Perna '' is a genus of mussels, marine bivalve molluscs in the family Mytilidae.Gofas, S. (2010). Perna Philipsson, 1788. In: Bouchet, P.; Gofas, S.; Rosenberg, G. (2010) World Marine Mollusca database. Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=138229 on 16 August 2012 Not to be confused with ''Perna'' Bruguière, 1789 , synonym of '' Isognomon'' Lightfoot, 1786 Species Species within the genus ''Perna '' include: * ''Perna canaliculus'' (Gmelin, 1791) New Zealand green-lipped mussel * '' Perna perna'' (Linnaeus, 1758) * † '' Perna tetleyi'' (Powell & Bartrum, 1929) * ''Perna viridis'': Asian green mussel (Linnaeus, 1758) Species brought into synonymy: * ''Perna africana'' (Chemnitz, 1785): synonym of ''Perna perna'' (Linnaeus, 1758) * ''Perna confusa'' Angas, 1871: synonym of '' Limnoperna securis'' (Lamarck, 1819) * ''Perna fulgida'' H. Adams, 1870: synonym of ''Lioberus ligneus'' (Reeve, 1858) * ''Per ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Latin
Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the Roman Republic it became the dominant language in the Italian region and subsequently throughout the Roman Empire. Even after the fall of Western Rome, Latin remained the common language of international communication, science, scholarship and academia in Europe until well into the 18th century, when other regional vernaculars (including its own descendants, the Romance languages) supplanted it in common academic and political usage, and it eventually became a dead language in the modern linguistic definition. Latin is a highly inflected language, with three distinct genders (masculine, feminine, and neuter), six or seven noun cases (nominative, accusative, genitive, dative, ablative, and vocative), five declensions, four verb conjuga ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
French Language
French ( or ) is a Romance language of the Indo-European family. It descended from the Vulgar Latin of the Roman Empire, as did all Romance languages. French evolved from Gallo-Romance, the Latin spoken in Gaul, and more specifically in Northern Gaul. Its closest relatives are the other langues d'oïl—languages historically spoken in northern France and in southern Belgium, which French ( Francien) largely supplanted. French was also influenced by native Celtic languages of Northern Roman Gaul like Gallia Belgica and by the ( Germanic) Frankish language of the post-Roman Frankish invaders. Today, owing to France's past overseas expansion, there are numerous French-based creole languages, most notably Haitian Creole. A French-speaking person or nation may be referred to as Francophone in both English and French. French is an official language in 29 countries across multiple continents, most of which are members of the ''Organisation internationale de la Francophonie'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
English Language
English is a West Germanic language of the Indo-European language family, with its earliest forms spoken by the inhabitants of early medieval England. It is named after the Angles, one of the ancient Germanic peoples that migrated to the island of Great Britain. Existing on a dialect continuum with Scots, and then closest related to the Low Saxon and Frisian languages, English is genealogically West Germanic. However, its vocabulary is also distinctively influenced by dialects of France (about 29% of Modern English words) and Latin (also about 29%), plus some grammar and a small amount of core vocabulary influenced by Old Norse (a North Germanic language). Speakers of English are called Anglophones. The earliest forms of English, collectively known as Old English, evolved from a group of West Germanic (Ingvaeonic) dialects brought to Great Britain by Anglo-Saxon settlers in the 5th century and further mutated by Norse-speaking Viking settlers starting in the 8th and 9th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Federal Trade Commission
The Federal Trade Commission (FTC) is an independent agency of the United States government whose principal mission is the enforcement of civil (non-criminal) antitrust law and the promotion of consumer protection. The FTC shares jurisdiction over federal civil antitrust enforcement with the Department of Justice Antitrust Division. The agency is headquartered in the Federal Trade Commission Building in Washington, DC. The FTC was established in 1914 with the passage of the Federal Trade Commission Act, signed in response to the 19th-century monopolistic trust crisis. Since its inception, the FTC has enforced the provisions of the Clayton Act, a key antitrust statute, as well as the provisions of the FTC Act, et seq. Over time, the FTC has been delegated with the enforcement of additional business regulation statutes and has promulgated a number of regulations (codified in Title 16 of the Code of Federal Regulations). The broad statutory authority granted to the FTC provide ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iridescence
Iridescence (also known as goniochromism) is the phenomenon of certain surfaces that appear to gradually change color as the angle of view or the angle of illumination changes. Examples of iridescence include soap bubbles, feathers, butterfly wings and seashell nacre, and minerals such as opal. It is a kind of structural coloration that is due to wave interference of light in microstructures or thin films. Pearlescence is a related effect where some or most of the reflected light is white. The term pearlescent is used to describe certain paint finishes, usually in the automotive industry, which actually produce iridescent effects. Etymology The word ''iridescence'' is derived in part from the Greek word ἶρις ''îris'' ( gen. ἴριδος ''íridos''), meaning ''rainbow'', and is combined with the Latin suffix ''-escent'', meaning "having a tendency toward". Iris in turn derives from the goddess Iris of Greek mythology, who is the personification of the rainbow and ac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nacre
Nacre ( , ), also known as mother of pearl, is an organicinorganic composite material produced by some molluscs as an inner shell layer; it is also the material of which pearls are composed. It is strong, resilient, and iridescent. Nacre is found in some of the most ancient lineages of bivalves, gastropods, and cephalopods. However, the inner layer in the great majority of mollusc shells is porcellaneous, not nacreous, and this usually results in a non-iridescent shine, or more rarely in non-nacreous iridescence such as ''flame structure'' as is found in conch pearls. The outer layer of cultured pearls and the inside layer of pearl oyster and freshwater pearl mussel shells are made of nacre. Other mollusc families that have a nacreous inner shell layer include marine gastropods such as the Haliotidae, the Trochidae and the Turbinidae. Physical characteristics Structure and appearance Nacre is composed of hexagonal platelets of aragonite (a form of calcium carbonate) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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