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Trapiche Emerald (cropped)
Trapiche emerald is a rare variety of the gemstone emerald, characterized by a six-pointed radial pattern of ray-like spokes of dark impurities. It is one of several types of trapiche or trapiche-like minerals, which also include trapiche ruby, sapphire, garnet, chiastolite and tourmaline. The name comes from the Spanish term '' trapiche'', a sugar mill, because of the resemblance of the pattern to the spokes of a grinding wheel. Trapiche emeralds were first described by Émile Bertrand in 1879. They are generally only (and rarely) found in the western part of the Eastern Cordillera basin, in the Muzo, Coscuez and Peñas Blancas mines of Colombia (but likely not in Chivor as reported in older literature). Singular finds in Brazil and Madagascar have also been reported. The radial pattern exhibits considerable variance, and often includes a hexagonal structure at the core. There is not yet consensus about the mechanism by which the pattern forms, or the conditions required f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trapiche Emerald (cropped)
Trapiche emerald is a rare variety of the gemstone emerald, characterized by a six-pointed radial pattern of ray-like spokes of dark impurities. It is one of several types of trapiche or trapiche-like minerals, which also include trapiche ruby, sapphire, garnet, chiastolite and tourmaline. The name comes from the Spanish term '' trapiche'', a sugar mill, because of the resemblance of the pattern to the spokes of a grinding wheel. Trapiche emeralds were first described by Émile Bertrand in 1879. They are generally only (and rarely) found in the western part of the Eastern Cordillera basin, in the Muzo, Coscuez and Peñas Blancas mines of Colombia (but likely not in Chivor as reported in older literature). Singular finds in Brazil and Madagascar have also been reported. The radial pattern exhibits considerable variance, and often includes a hexagonal structure at the core. There is not yet consensus about the mechanism by which the pattern forms, or the conditions required f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Émile Bertrand
Émile Bertrand (1844–1909) was a French mineralogist, in honour of whom bertrandite was named by Alexis Damour. He also gave his name to the ''Bertrand lens'' or phase telescope. He studied at the Ecole des Mines in Paris and was a co-founder of the ''Société française de Minéralogie''. He wrote a book on the application of microscopy to mineralogical studies, "''De l'Application du microscope à l'étude de la minéralogie''" (1878); published a translation of Ernst Mach's work on the history of mechanics, "''La mécanique: exposé historique et critique de son développement''" (1904); and is credited with the design of a refractometer A refractometer is a laboratory or field device for the measurement of an index of refraction ( refractometry). The index of refraction is calculated from the observed refraction angle using Snell's law. For mixtures, the index of refraction the .... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asterism (gemmology)
An asterism () is a star-shaped concentration of reflected or refracted light from a gemstone. Asterisms can appear when a suitable stone is cut ''en cabochon'' i.e. shaped and polished (not faceted). A gemstone that exhibits this effect is referred to as a star stone or asteria. The best known is star sapphire, but many other minerals can also be asteria, usually due to impurities in the crystal structure. Archetype The archetypal asteria is the star sapphire, generally corundum with near uniform impurities which is bluish-grey and milky or opalescent, which when lit has a star of six rays. In the red instance stellate reflection is rarer; the star- ruby occasionally found with the star-sapphire in Sri Lanka is among the most valued of "fancy stones". Other examples are star- topaz and certain prized chatoyant (, ) chrysoberyl stones, particularly of the cymophane (yellow) variety. Description Asterism is generated by reflections of light from twin-lamellae or from ext ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dendrite (crystal)
A crystal dendrite is a crystal that develops with a typical multi-branching form. The name comes from the Greek word dendron (δενδρον) which means "tree", since the crystal's structure resembles that of a tree. These crystals can be synthesised by using a supercooled pure liquid, however they are also quite common in nature. The most common crystals in nature exhibit dendritic growth are snowflakes and frost on windows, but many minerals and metals can also be found in dendritic structures. History Maximum velocity principle The first dendritic patterns were discovered in palaeontology and are often mistaken for fossils because of their appearance. The first theory for the creation of these patterns was published by Nash and Glicksman in 1974, they used a very mathematical method and derived a non-linear integro-differential equation for a classical needle growth. However they only found an inaccurate numerical solution close to the tip of the needle and they f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shale
Shale is a fine-grained, clastic sedimentary rock formed from mud that is a mix of flakes of clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4) and tiny fragments (silt-sized particles) of other minerals, especially quartz and calcite.Blatt, Harvey and Robert J. Tracy (1996) ''Petrology: Igneous, Sedimentary and Metamorphic'', 2nd ed., Freeman, pp. 281–292 Shale is characterized by its tendency to split into thin layers ( laminae) less than one centimeter in thickness. This property is called '' fissility''. Shale is the most common sedimentary rock. The term ''shale'' is sometimes applied more broadly, as essentially a synonym for mudrock, rather than in the more narrow sense of clay-rich fissile mudrock. Texture Shale typically exhibits varying degrees of fissility. Because of the parallel orientation of clay mineral flakes in shale, it breaks into thin layers, often splintery and usually parallel to the otherwise indistinguishable beddin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chivor
Chivor is a town and municipality in the Eastern Boyacá Province, part of the Colombian department of Boyacá. The mean temperature of the village in the Tenza Valley is and Chivor is located at from the department capital Tunja. Economic activity includes emerald mining. Borders Bordered to the north with the municipality of Macanal; to the south with Ubalá, Cundinamarca, on the east with the municipality of Santa María, and the west by the municipality of Almeida. Etymology Chivor comes from Chibcha and means "Our farmfields - our mother" or "Green and rich land". The latter refers to the rich emerald deposits.Etymology Chivor - Excelsio.net History Chivor was inhabited by the |
Muzo
Muzo () is a town and municipality in the Western Boyacá Province, part of the department of Boyacá, Colombia. It is widely known as the world capital of emeralds for the mines containing the world's highest quality gems of this type. Muzo is situated at a distance of from the departmental capital Tunja and from the capital of the Western Boyacá Province, Chiquinquirá. The urban centre is at an altitude of above sea level. Muzo borders Otanche and San Pablo de Borbur in the north, Maripí and Coper in the east, Quípama in the west and the department of Cundinamarca in the south. Etymology The town of Muzo was called Villa de la Santísima Trinidad de los Muzos, or simply Trinidad, when the Spanish conquistadors first founded the settlement in western Boyacá. Muzo is the autonym of the Muzo, the indigenous people who inhabited the region before the Spanish conquest. Climate The median temperature of Muzo is and the annual precipitation . History Before the Sp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cordillera Oriental (Colombia)
The Cordillera Oriental ( en, Eastern Ranges) is the widest of the three branches of the Colombian Andes. The range extends from south to north dividing from the Colombian Massif in Huila Department to Norte de Santander Department where it splits into the Serranía del Perijá and the Cordillera de Mérida in Venezuelan Andes. The highest peak is Ritacuba Blanco at in the Sierra Nevada del Cocuy. Geography The western part of the Cordillera Oriental belongs to the Magdalena River basin, while the eastern part includes the river basins of the Amazon River, Orinoco River, and Catatumbo River. Within it, the Altiplano Cundiboyacense and the Sierra Nevada del Cocuy (with the only snowy peaks in this mountain range) stand out. The mountain range contains the most páramos in the world. Protected areas * Cueva de los Guácharos * Chingaza National Natural Park * Yariguíes National Park * Sierra Nevada del Cocuy * Sumapaz Páramo * Tamá National Natural Park * Los Estoraques Uni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gems & Gemology
''Gems & Gemology'' is a quarterly scientific journal published by the Gemological Institute of America. Each issue is devoted to research on diamonds, gemstones, and pearls. Topics include geographic sources, imitations and synthetics, treatments, and identification techniques. Established in January 1934, ''Gems & Gemology'' is geared toward jewelry professionals and gemologists. Issues contain research articles, updates from the GIA Laboratory and international gemology news. ''Gems & Gemology'' is abstracted and indexed by the Science Citation Index. According to the ''Journal Citation Reports'', its 2016 impact factor The impact factor (IF) or journal impact factor (JIF) of an academic journal is a scientometric index calculated by Clarivate that reflects the yearly mean number of citations of articles published in the last two years in a given journal, as i ... is 0.793, ranking it 24th out of 29 journals in the category "Mineralogy". References External links * Ge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Emerald
Emerald is a gemstone and a variety of the mineral beryl (Be3Al2(SiO3)6) colored green by trace amounts of chromium or sometimes vanadium.Hurlbut, Cornelius S. Jr. and Kammerling, Robert C. (1991) ''Gemology'', John Wiley & Sons, New York, p. 203, . Beryl has a hardness of 7.5–8 on the Mohs scale. Most emeralds are highly included, so their toughness (resistance to breakage) is classified as generally poor. Emerald is a cyclosilicate. Etymology The word "emerald" is derived (via fro, esmeraude and enm, emeraude), from Vulgar Latin: ''esmaralda''/''esmaraldus'', a variant of Latin ''smaragdus'', which was a via grc, σμάραγδος (smáragdos; "green gem") from a Semitic language. According to Webster's Dictionary the term emerald was first used in the 14th century. Properties determining value Emeralds, like all colored gemstones, are graded using four basic parameters–the four ''C''s of connoisseurship: ''color'', ''clarity,'' ''cut'' and ''carat weight''. N ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trapiche
A trapiche is a mill made of wooden rollers used to extract juice from fruit, originally olives, and since the Middle Ages, sugar cane as well. By extension the word is also sometimes applied to the location of the mill, whether the workshop or the entire plantation. Etymology The word has its origin in the Latin '' trapetum'' that means oil mill. From the Sicilian language ''trappituCharles Verlinden & Eberhard Schmitt, ''Die mittelalterlichen Ursprünge der europäischen Expansion,'' tom I de ''Dokumente zur Geschichte der europäischen Expansion,'' Wiesbaden, Otto Harrassowitz Verlag, 1986, pàgina 169, '' the term, crossing the Mozarab Valencia, with its typical change of termination to «-ig» via the Catalan language (''trapig'' -Gandía, 1536-, ''trapitz de canyamel'' -Mallorca, 1466-) has arrived to the other languages of the Iberian peninsula as ''trapiche.'' In the documents of the Duke of Gandía from the beginning of the fifteen century, one can see the term «trapig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tourmaline
Tourmaline ( ) is a crystalline silicate mineral group in which boron is compounded with elements such as aluminium, iron, magnesium, sodium, lithium, or potassium. Tourmaline is a gemstone and can be found in a wide variety of colors. The term is derived from the Sinhalese "tōramalli", which refers to the carnelian gemstones. History Brightly colored Ceylonese gem tourmalines were brought to Europe in great quantities by the Dutch East India Company to satisfy a demand for curiosities and gems. Tourmaline was sometimes called the "Ceylonese Magnet" because it could attract and then repel hot ashes due to its pyroelectric properties. Tourmalines were used by chemists in the 19th century to polarize light by shining rays onto a cut and polished surface of the gem. Species and varieties Commonly encountered species and varieties: Schorl species: : Brownish black to black—''schorl'', Dravite species: from the Drave district of Carinthia : Dark yellow to brownish blac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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