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1GURUDAS.EL LIBRO DE LAS ESENCIAS FLORALESTRADUCCIN LIBRE AL CASTELLANONDICE VINCULAR (HACER CLIC SOBRE EL CAPTULO O ESENCIA A LEER)2PRLOGO PREFACIO INTRODUCCIN PRINCIPIOS ACERCA DE LA CANALIZACIN PARTE I CAPTULO I: PRINCIPIOS GENERALES Y USO HISTRICO DE LAS ESENCIAS FLORALES CAPTULO II: EL DOCTOR BACH Y LAS FLORES DE BACH CAPTULO III: PREPARACIN DE LAS ESENCIAS FLORALES CAPTULO IV: ALMACENAMIENTO, PROTECCIN Y LIMPIEZA DE LAS ESENCIAS FLORALES. CAPTULO V: CMO ACTAN SOBRE LA GENTE LAS ESENCIAS FLORALES, LOS REMEDIOS HOMEOPTICOS Y LOS CRISTALES TERAPUTICOS. CAPTULO VI: LA RELACIN DE LAS ESENCIAS FLORALES CON LA HOMEOPATA, LAS HIERBAS Y LAS GEMAS. CAPTULO VII: CONSEJOS A LOS TERAPEUTAS Y A LOS PACIENTES. CAPTULO VIII: TERAPIAS POR INMERSIN.
A rich seam of iridescent opal encased in matrix General Category (repeating unit). Common Rough Opal Opal is a form of (SiO 2 nH 2O); its water content may range from 3 to 21% by weight, but is usually between 6 and 10%. Because of its amorphous character, it is classed as a, unlike crystalline forms of silica, which are classed as minerals. It is deposited at a relatively low temperature and may occur in the fissures of almost any kind of, being most commonly found with,. Opal is the national of Australia. There are two broad classes of opal: precious and common.
Precious opal displays play-of-color , common opal does not. Play-of-color is defined as 'a pseudochromatic optical effect resulting in flashes of colored light from certain minerals, as they are turned in white light.' The internal structure of precious opal causes it to light, resulting in play-of-color. Depending on the conditions in which it formed, opal may be transparent, translucent or opaque and the background color may be white, black or nearly any color of the visual spectrum.
Black opal is considered to be the rarest, whereas white, gray and green are the most common. Precious opal replacing backbone; display specimen, Precious opal shows a variable interplay of internal colors, and though it is a mineraloid, it has an internal structure. At microscopic scales, precious opal is composed of silica spheres some 150 to 300 in diameter in a hexagonal or cubic. It was shown by J. Sanders in the mid-1960s that these ordered silica spheres produce the internal colors by causing the and of light passing through the microstructure of the opal. The regularity of the sizes and the packing of these spheres determines the quality of precious opal.
Where the distance between the regularly packed planes of spheres is around half the wavelength of a component of, the light of that wavelength may be subject to diffraction from the created by the stacked planes. The colors that are observed are determined by the spacing between the planes and the orientation of planes with respect to the incident light. The process can be described by of diffraction. Visible light cannot pass through large thicknesses of the opal. This is the basis of the optical in a. The notion that opals are photonic crystals for visible light was expressed in 1995 by 's group. In addition, microfractures may be filled with secondary silica and form thin inside the opal during solidification.
The term is commonly used to describe this unique and beautiful phenomenon, which in gemology is termed. In gemology, opalescence is applied to the hazy-milky- sheen of common or potch opal which does not show a play of color. Is a form of. For use, most opal is cut and polished to form a. 'Solid' opal refers to polished stones consisting wholly of precious opal.
Opals too thin to produce a 'solid' may be combined with other materials to form attractive gems. An opal doublet consists of a relatively thin layer of precious opal, backed by a layer of dark-colored material, most commonly ironstone, dark or black common opal (potch), onyx, or obsidian. The darker backing emphasizes the play of color, and results in a more attractive display than a lighter potch. An opal triplet is similar to a doublet, but has a third layer, a domed cap of clear or plastic on the top. The cap takes a high polish and acts as a protective layer for the opal. The top layer also acts as a magnifier, to emphasize the play of color of the opal beneath, which is often of lower quality. Triplet opals therefore have a more artificial appearance, and are not classed as precious opal.
Jewelry applications of precious opal can be somewhat limited by opal's sensitivity to heat due primarily to its relatively high water content and predisposition to scratching. Combined with modern techniques of polishing, doublet opal produces a similar effect to black or boulder opal at a fraction of the price. Doublet opal also has the added benefit of having genuine opal as the top visible and touchable layer, unlike triplet opals. Common opal.
White and blue opal from Slovakia Besides the varieties that show a play of color, the other kinds of common opal include the milk opal, milky bluish to greenish (which can sometimes be of gemstone quality); opal, which is honey-yellow with a resinous luster;, which is caused by the replacement of the organic material in wood with opal;, which is brown or grey;, a colorless glass-clear opal sometimes called Muller's glass;, also called, deposited around or; and, the accumulations of shells or tests. Common opal often displays a hazy-milky- sheen from within the stone. In, this optical effect is strictly defined as which is a form of. Other varieties of opal. Brightness of the fire in opal ranges on a scale of 1 to 5 (with 5 being the brightest) Fire opal is a transparent to translucent opal, with warm body colors of yellow to orange to red. Although it does not usually show any play of color, occasionally a stone will exhibit bright green flashes. The most famous source of fire opals is the state of in Mexico; these opals are commonly called Mexican fire opals.
Fire opals that do not show play of color are sometimes referred to as jelly opals. Mexican opals are sometimes cut in their rhyolitic host material if it is hard enough to allow cutting and polishing. This type of Mexican opal is referred to as a Cantera opal. Also, a type of opal from Mexico, referred to as Mexican water opal, is a colorless opal which exhibits either a bluish or golden internal sheen. Girasol opal is a term sometimes mistakenly and improperly used to refer to fire opals, as well as a type of transparent to semitransparent type milky quartz from Madagascar which displays an asterism, or star effect, when cut properly. However, the true girasol opal is a type of opal that exhibits a bluish glow or sheen that follows the light source around.
It is not a play of color as seen in precious opal, but rather an effect from microscopic inclusions. It is also sometimes referred to as water opal, too, when it is from Mexico. The two most notable locations of this type of opal are and Mexico. Peruvian opal (also called blue opal) is a semi-opaque to opaque blue-green stone found in Peru, which is often cut to include the matrix in the more opaque stones. It does not display play of color. Blue opal also comes from in the region, as well as from around the.
Opal is also formed. Diatoms are a form of algae which, when they die, often form layers at the bottoms of lakes, bays, or oceans. Their cell walls are made up of hydrated silicon dioxide which gives them structural coloration and therefore the appearance of tiny opals when viewed under a microscope. These cell walls or 'tests' form the “grains” for the. This sedimentary rock is white, opaque, and chalky in texture. Diatomite has multiple industrial uses such as filtering or adsorbing since it has a fine particle size and very porous nature, and gardening to increase water adsorption.
History Opal was rare and very valuable in antiquity. In Europe it was a gem prized by royalty. Until the opening of vast deposits in Australia in the 19th century the only known source was beyond the Roman frontier in. Boulder opal, Carisbrooke Station near Australian opal has often been cited as accounting for 95–97% of the world's supply of precious opal, with the state of accounting for 80% of the world's supply. Recent data suggests that the world supply of precious opal may have changed. In 2012, Ethiopian opal production was estimated to be 14,000 kg (31,000 lb) by the United States Geological Survey.
USGS data from the same period (2012), reveals that Australian opal production to be $41 million. Because of the units of measurement, it is not possible to directly compare Australian and Ethiopian opal production, but these data and others suggest that the traditional percentages given for Australian opal production may be overstated. Yet, the validity of data in the USGS report appears to conflict with that of Laurs et al. and Mesfinwho estimated the 2012 Ethiopian opal output (from ) to be only 750 kg (1,650 lb). Australia The town of in is a major source of opal.
The world's largest and most valuable gem opal ' was found in August 1956 at the 'Eight Mile' opal field in Coober Pedy. It weighs 17,000 carats (3.4 kg; 7.5 lb) and is 11 inches (280 mm) long, with a height of 4 3⁄ 4 in (120 mm) and a width of 4 1⁄ 2 in (110 mm). The located about 250 km (160 mi) north west of Coober Pedy has also produced large quantities of crystal opal and the rarer black opal. Over the years, it has been sold overseas incorrectly as Coober Pedy opal.
The black opal is said to be some of the best examples found in Australia. In South Australia is also a major producer of matrix opal, crystal opal, and black opal. Another Australian town, in, is the main source of black opal, opal containing a predominantly dark background (dark gray to blue-black displaying the play of color). Boulder opal consists of and fracture fillings in a dark siliceous matrix. It is found sporadically in western Queensland, from Kynuna in the north, to and in the south. Its largest quantities are found around and in. Australia also has fossil remains, including dinosaur bones in New South Wales and South Australia, and marine creatures in South Australia.
Ethiopia Although it has been reported that Northern African opal was used to make tools as early as 4000 BC, the first published report of gem opal from appeared in 1994, with the discovery of precious opal in the Menz Gishe District, North Shewa Province. The opal, found mostly in the form of nodules, was of volcanic origin and was found predominantly within weathered layers of. This Shewa Province opal was mostly dark brown in color and had a tendency to crack. These qualities made it unpopular in the gem trade. In 2008, a new opal deposit was found approximately 180 km north of Shewa Province, near the town of, in Ethiopia's. The Wollo Province opal was different from the previous Ethiopian opal finds in that it more closely resembled the sedimentary opals of Australia and Brazil, with a light background and often vivid play-of-color.
Wollo Province opal, more commonly referred to as 'Welo' or 'Wello' opal, has become the dominant Ethiopian opal in the gem trade. Multicolored rough opal specimen from Virgin Valley, Nevada, US The Virgin Valley opal fields of in northern produce a wide variety of precious black, crystal, white, fire, and lemon opal. The black fire opal is the official gemstone of Nevada. Most of the precious opal is partial wood replacement.
The precious opal is hosted and found within a subsurface horizon or zone of in place which is considered a 'lode' deposit. Opals which have weathered out of the in-place deposits are alluvial and considered.age opalised teeth, bones, fish, and a snake head have been found.
Some of the opal has high water content and may desiccate and crack when dried. The largest producing mines of Virgin Valley have been the famous Rainbow Ridge, Royal Peacock, Bonanza, Opal Queen, and WRT Stonetree/Black Beauty mines. The largest unpolished black opal in the Smithsonian Institution, known as the 'Roebling opal', came out of the tunneled portion of the Rainbow Ridge Mine in 1917, and weighs 2,585 carats (517.0 g; 18.24 oz).
The largest polished black opal in the comes from the Royal Peacock opal mine in the Virgin Valley, weighing 160 carats (32 g; 1.1 oz), known as the 'Black Peacock'. The crystal structure of crystalline α. Locally, the structures of some opals, opal-C, are similar to this. The structure of low-pressure of anhydrous consist of frameworks of fully corner bonded tetrahedra of SiO 4. The higher temperature polymorphs of silica and are frequently the first to crystallize from amorphous anhydrous silica, and the local structures of microcrystalline opals also appear to be closer to that of cristobalite and tridymite than to quartz.
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