79-542: Esmeraldas is the word for ' emeralds ' in Portuguese and Spanish. It may refer to: Brazil [ edit ] Esmeraldas, Minas Gerais Ecuador [ edit ] Esmeraldas, Ecuador , a port city Esmeraldas Canton Esmeraldas Province Esmeraldas River See also [ edit ] All pages with titles containing Esmeraldas Esmeralda (disambiguation) [REDACTED] Topics referred to by
158-493: A "synthetic" stone. The FTC says: "§ 23.23(c) It is unfair or deceptive to use the word "laboratory-grown", "laboratory-created", "[manufacturer name]-created", or "synthetic" with the name of any natural stone to describe any industry product unless such industry product has essentially the same optical, physical, and chemical properties as the stone named." The virtue of the Emerald is to counteract poison. They say that if
237-464: A certificate from a licensed, independent gemology laboratory. Other treatments, for example the use of green-tinted oil, are not acceptable in the trade. Gems are graded on a four-step scale; none , minor , moderate and highly enhanced. These categories reflect levels of enhancement, not clarity . A gem graded none on the enhancement scale may still exhibit visible inclusions. Laboratories apply these criteria differently. Some gemologists consider
316-468: A certificate from an independent gemological laboratory attesting to "no evidence of heat treatment". Yogo sapphires do not need heat treating because their cornflower blue color is attractive out of the ground; they are generally free of inclusions , and have high uniform clarity. When Intergem Limited began marketing the Yogo in the 1980s as the world's only guaranteed untreated sapphire, heat treatment
395-399: A dominant red body color. This is generally caused by traces of chromium (Cr ) substituting for the (Al ) ion in the corundum structure. The color can be modified by both iron and trapped hole color centers. Unlike localized ("intra-atomic") absorption of light, which causes color for chromium and vanadium impurities, blue color in sapphires comes from intervalence charge transfer, which is
474-500: A grayish-green hue is a dull-green hue. Emeralds tend to have numerous inclusions and surface-breaking fissures . Unlike diamonds, where the loupe standard (i.e., 10× magnification) is used to grade clarity, emeralds are graded by eye. Thus, if an emerald has no visible inclusions to the eye (assuming normal visual acuity) it is considered flawless. Stones that lack surface breaking fissures are extremely rare and therefore almost all emeralds are treated ("oiled", see below) to enhance
553-410: A lot of strain due to the high thermal gradient between the flame and surrounding air. To release this strain, the now finger-shaped crystal will be tapped with a chisel to split it into two halves. Due to the vertical layered growth of the crystal and the curved upper growth surface (which starts from a drop), the crystals will display curved growth lines following the top surface of the boule. This
632-467: A medium-dark tone, command the highest prices. The relative non-uniformity motivates the cutting of emeralds in cabochon form, rather than faceted shapes. Faceted emeralds are most commonly given an oval cut, or the signature emerald cut, a rectangular cut with facets around the top edge. Most emeralds are oiled as part of the post- lapidary process, in order to fill in surface-reaching cracks so that clarity and stability are improved. Cedar oil , having
711-490: A pure verdant green hue as described below, but also a high degree of transparency to be considered a top gemstone. This member of the beryl family ranks among the traditional "big four" gems along with diamonds , rubies and sapphires . In the 1960s, the American jewelry industry changed the definition of emerald to include the green vanadium-bearing beryl. As a result, vanadium emeralds purchased as emeralds in
790-400: A rate of 1 to 100 mm per hour. The alumina crystallizes on the end, creating long carrot-shaped boules of large size up to 200 kg in mass. Synthetic sapphire is also produced industrially from agglomerated aluminum oxide, sintered and fused (such as by hot isostatic pressing ) in an inert atmosphere, yielding a transparent but slightly porous polycrystalline product. In 2003,
869-503: A respected laboratory such as GIA , Lotus Gemology , or SSEF , is often required by buyers before they will make a purchase. Sapphires in colors other than blue are called "fancy" sapphires. "Parti sapphire" is used for multicolor stones with zoning of different colors (hues), but not different shades. Fancy sapphires are found in yellow, orange, green, brown, purple, violet, and practically any other hue. Gemstone color can be described in terms of hue , saturation , and tone . Hue
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#1732776895657948-426: A similar refractive index , is often used in this widely adopted practice. Other liquids, including synthetic oils and polymers with refractive indexes close to that of emeralds, such as Opticon , are also used. The least expensive emeralds are often treated with epoxy resins, which are effective for filling stones with many fractures. These treatments are typically applied in a vacuum chamber under mild heat, to open
1027-509: A thin layer of emerald on top of natural colorless beryl stones. Later, from 1965 to 1970, the Linde Division of Union Carbide produced completely synthetic emeralds by hydrothermal synthesis. According to their patents (attributable to E.M. Flanigen ), acidic conditions are essential to prevent the chromium (which is used as the colorant) from precipitating. Also, it is important that the silicon-containing nutrient be kept away from
1106-417: A variety of shades. Corundum that contains extremely low levels of chromophores is near colorless. Completely colorless corundum generally does not exist in nature. If trace amounts of iron are present, a very pale yellow to green color may be seen. However, if both titanium and iron impurities are present together, and in the correct valence states, the result is a blue color. Intervalence charge transfer
1185-556: A venomous animal should look at it, it will become blinded. The gem also acts as a preservative against epilepsy; it cures leprosy, strengthens sight and memory, checks copulation, during which act it will break, if worn at the time on the finger. Sapphire Sapphire is a precious gemstone , a variety of the mineral corundum , consisting of aluminium oxide ( α- Al 2 O 3 ) with trace amounts of elements such as iron , titanium , cobalt , lead , chromium , vanadium , magnesium , boron , and silicon . The name sapphire
1264-442: Is a process that produces a strong colored appearance at a low percentage of impurity. While at least 1% chromium must be present in corundum before the deep red ruby color is seen, sapphire blue is apparent with the presence of only 0.01% of titanium and iron. Colorless sapphires, which are uncommon in nature, were once used as diamond substitutes in jewelry, and are presently used as accent stones. The most complete description of
1343-459: Is a specific change in energy for the electron, and electromagnetic energy is absorbed. The wavelength of the energy absorbed corresponds to yellow light. When this light is subtracted from incident white light, the complementary color blue results. Sometimes when atomic spacing is different in different directions, there is resulting blue-green dichroism . Purple sapphires contain trace amounts of chromium and iron plus titanium and come in
1422-486: Is a type of sapphire that exhibits a star-like phenomenon known as asterism ; red stones are known as "star rubies". Star sapphires contain intersecting needle-like inclusions following the underlying crystal structure that causes the appearance of a six-rayed "star"-shaped pattern when viewed with a single overhead light source. The inclusion is often the mineral rutile , a mineral composed primarily of titanium dioxide . The stones are cut en cabochon , typically with
1501-439: Is added to the flame, causing it to burn slightly hotter. This expands the growing crystal laterally. At the same time, the pedestal is lowered at the same rate that the crystal grows vertically. The alumina in the flame is slowly deposited, creating a teardrop shaped " boule " of sapphire material. This step is continued until the desired size is reached, the flame is shut off and the crystal cools. The now elongated crystal contains
1580-494: Is called padparadscha . Significant sapphire deposits are found in Australia , Afghanistan , Cambodia , Cameroon , China ( Shandong ), Colombia , Ethiopia , India Jammu and Kashmir ( Padder , Kishtwar ), Kenya , Laos , Madagascar , Malawi , Mozambique , Myanmar ( Burma ), Nigeria , Rwanda , Sri Lanka , Tanzania , Thailand , United States ( Montana ) and Vietnam . Sapphire and rubies are often found in
1659-414: Is classified as generally poor. Emerald is a cyclosilicate . The word "emerald" is derived (via Old French : esmeraude and Middle English : emeraude ), from Vulgar Latin : esmaralda/esmaraldus , a variant of Latin smaragdus , which was via Ancient Greek : σμάραγδος (smáragdos; "green gem"). The Greek word may have a Semitic, Sanskrit or Persian origin. According to Webster's Dictionary
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#17327768956571738-451: Is common practice to heat natural sapphires to improve or enhance their appearance. This is done by heating the sapphires in furnaces to temperatures between 800 and 1,800 °C (1,470 and 3,270 °F) for several hours, or even weeks at a time. Different atmospheres may be used. Upon heating, the stone becomes bluer in color, but loses some of the rutile inclusions (silk). When high temperatures (1400 °C+) are used, exsolved rutile silk
1817-428: Is commonly understood as the " color " of the gemstone. Saturation refers to the vividness or brightness of the hue, and tone is the lightness to darkness of the hue. Blue sapphire exists in various mixtures of its primary (blue) and secondary hues, various tonal levels (shades) and at various levels of saturation (vividness). Blue sapphires are evaluated based upon the purity of their blue hue. Violet and green are
1896-452: Is considered a supplementary test when making a natural versus synthetic determination, as many, but not all, natural emeralds are inert to ultraviolet light. Many synthetics are also UV inert. Synthetic emeralds are often referred to as "created", as their chemical and gemological composition is the same as their natural counterparts. The U.S. Federal Trade Commission (FTC) has very strict regulations as to what can and what cannot be called
1975-556: Is derived from the Latin word sapphirus , itself from the Greek word sappheiros ( σάπφειρος ), which referred to lapis lazuli . It is typically blue, but natural "fancy" sapphires also occur in yellow, purple, orange, and green colors; "parti sapphires" show two or more colors. Red corundum stones also occur, but are called rubies rather than sapphires. Pink-colored corundum may be classified either as ruby or sapphire depending on
2054-477: Is different from Wikidata All article disambiguation pages All disambiguation pages Emerald Emerald is a gemstone and a variety of the mineral beryl (Be 3 Al 2 (SiO 3 ) 6 ) colored green by trace amounts of chromium or sometimes vanadium . Beryl has a hardness of 7.5–8 on the Mohs scale . Most emeralds have many inclusions , so their toughness (resistance to breakage)
2133-409: Is dissolved and it becomes clear under magnification. The titanium from the rutile enters solid solution and thus creates with iron the blue color. The inclusions in natural stones are easily seen with a jeweler's loupe . Evidence of sapphire and other gemstones being subjected to heating goes back at least to Roman times. Un-heated natural stones are somewhat rare and will often be sold accompanied by
2212-557: Is heavily tilted to the red end of the spectrum, thus tipping the balance to red. Color-change sapphires colored by the Cr + Fe/Ti chromophores generally change from blue or violet-blue to violet or purple. Those colored by the V chromophore can show a more pronounced change, moving from blue-green to purple. Certain synthetic color-change sapphires have a similar color change to the natural gemstone alexandrite and they are sometimes marketed as "alexandrium" or "synthetic alexandrite". However,
2291-432: Is in contrast to natural corundum crystals, which feature angular growth lines expanding from a single point and following the planar crystal faces. Chemical dopants can be added to create artificial versions of the ruby, and all the other natural colors of sapphire, and in addition, other colors never seen in geological samples. Artificial sapphire material is identical to natural sapphire, except it can be made without
2370-416: Is required of any mode of enhancement that has a significant effect on the gem's value. There are several ways of treating sapphire. Heat-treatment in a reducing or oxidizing atmosphere (but without the use of any other added impurities) is commonly used to improve the color of sapphires, and this process is sometimes known as "heating only" in the gem trade. In contrast, however, heat treatment combined with
2449-666: Is the world's second biggest producer, with its Kafubu River area deposits (Kagem Mines) about 45 km (28 mi) southwest of Kitwe responsible for 20% of the world's production of gem-quality stones in 2004. In the first half of 2011, the Kagem Mines produced 3.74 tons of emeralds. Emeralds are found all over the world in countries such as Afghanistan, Australia, Austria, Brazil, Bulgaria, Cambodia, Canada, China, Egypt, Ethiopia, France, Germany, India, Kazakhstan, Madagascar, Mozambique, Namibia, Nigeria, Norway, Pakistan, Russia, Somalia, South Africa, Spain, Switzerland, Tanzania,
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2528-709: Is thought to be the third-largest star sapphire, and is currently on display at the American Museum of Natural History in New York City . The 182-carat Star of Bombay , mined in Sri Lanka and located in the National Museum of Natural History in Washington, D.C. , is another example of a large blue star sapphire. The value of a star sapphire depends not only on the weight of the stone, but also
2607-633: The Star of India , The Star of Adam and the Star of Bombay originate from Sri Lankan mines. Madagascar is the world leader in sapphire production (as of 2007) specifically its deposits in and around the town of Ilakaka . Prior to the opening of the Ilakaka mines, Australia was the largest producer of sapphires (such as in 1987). In 1991 a new source of sapphires was discovered in Andranondambo, southern Madagascar. The exploitation started in 1993, but
2686-566: The chromium chromophore that creates the red color of ruby, combined with the iron + titanium chromophore that produces the blue color in sapphire. A rarer type, which comes from the Mogok area of Myanmar, features a vanadium chromophore, the same as is present in Verneuil synthetic color-change sapphire. Virtually all gemstones that show the "alexandrite effect" (color change or ' metamerism ') show similar absorption/transmission features in
2765-545: The insulating substrates of special-purpose solid-state electronics such as integrated circuits and GaN -based blue LEDs . Sapphire is the birthstone for September and the gem of the 45th anniversary . A sapphire jubilee occurs after 65 years. Sapphire is one of the two gem-varieties of corundum , the other being ruby (defined as corundum in a shade of red). Although blue is the best-known sapphire color, it occurs in other colors, including gray and black, and also can be colorless. A pinkish orange variety of sapphire
2844-665: The 12.00 carat Cartier sapphire ring at US$ 193,975 per carat, then with a 17.16 carat sapphire at US$ 236,404, and again in June 2015 when the per-carat auction record was set at US$ 240,205. At present, the world record price-per-carat for sapphire at auction is held by a sapphire from Kashmir in a ring, which sold in October 2015 for approximately US$ 242,000 per carat ( HK$ 52,280,000 in total, including buyer's premium, or more than US$ 6.74 million). Sapphires can be treated by several methods to enhance and improve their clarity and color. It
2923-524: The French chemist Auguste Verneuil announced a process for producing synthetic ruby crystals. In the flame-fusion ( Verneuil process ), fine alumina powder is added to an oxyhydrogen flame , and this is directed downward against a ceramic pedestal. Following the successful synthesis of ruby, Verneuil focused his efforts on sapphire. Synthesis of blue sapphire came in 1909, after chemical analyses of sapphire suggested to Verneuil that iron and titanium were
3002-584: The United States are not recognized as such in the United Kingdom and Europe. In America, the distinction between traditional emeralds and the new vanadium kind is often reflected in the use of terms such as "Colombian emerald". In gemology , color is divided into three components: hue , saturation , and tone . Emeralds occur in hues ranging from yellow-green to blue-green, with the primary hue necessarily being green. Yellow and blue are
3081-715: The United States, Zambia, and Zimbabwe. In the US, emeralds have been found in Connecticut , Montana , Nevada , North Carolina , and South Carolina . In 1998, emeralds were discovered in the Yukon Territory of Canada. Since the onset of concerns regarding diamond origins, research has been conducted to determine if the mining location could be determined for an emerald already in circulation. Traditional research used qualitative guidelines such as an emerald's color, style and quality of cutting, type of fracture filling, and
3160-517: The anthropological origins of the artifacts bearing the mineral to determine the emerald's mine location. More recent studies using energy-dispersive X-ray spectroscopy methods have uncovered trace chemical element differences between emeralds, including ones mined in close proximity to one another. American gemologist David Cronin and his colleagues have extensively examined the chemical signatures of emeralds resulting from fluid dynamics and subtle precipitation mechanisms, and their research demonstrated
3239-405: The apparent clarity. The inclusions and fissures within an emerald are sometimes described as jardin (French for garden ), because of their mossy appearance. Imperfections are unique for each emerald and can be used to identify a particular stone. Eye-clean stones of a vivid primary green hue (as described above), with no more than 15% of any secondary hue or combination (either blue or yellow) of
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3318-698: The area of Franklin, North Carolina . The sapphire deposits of Kashmir are well known in the gem industry, although their peak production took place in a relatively short period at the end of the nineteenth and early twentieth centuries. These deposits are located in the Paddar Valley of the Jammu region of Jammu and Kashmir in India. They have a superior vivid blue hue, coupled with a mysterious and almost sleepy quality, described by some gem enthusiasts as ‘blue velvet”. Kashmir-origin contributes meaningfully to
3397-543: The biggest problem the Yogo mine faced was not competition from heated sapphires, but the fact that the Yogo stones could never produce quantities of sapphire above one carat after faceting. As a result, it has remained a niche product, with a market that largely exists in the US. Lattice ('bulk') diffusion treatments are used to add impurities to the sapphire to enhance color. This process was originally developed and patented by Linde Air division of Union Carbide and involved diffusing titanium into synthetic sapphire to even out
3476-415: The blue color. It was later applied to natural sapphire. Today, titanium diffusion often uses a synthetic colorless sapphire base. The color layer created by titanium diffusion is extremely thin (less than 0.5 mm). Thus repolishing can and does produce slight to significant loss of color. Chromium diffusion has been attempted, but was abandoned due to the slow diffusion rates of chromium in corundum. In
3555-466: The body color, visibility, and intensity of the asterism. The color of the stone has more impact on the value than the visibility of the star. Since more transparent stones tend to have better colors, the most expensive star stones are semi-transparent "glass body" stones with vivid colors. On 28 July 2021, the world's largest cluster of star sapphires, weighing 510 kg (1,120 lb), was unearthed from Ratnapura, Sri Lanka. This star sapphire cluster
3634-433: The cause of the blue color. Verneuil patented the process of producing synthetic blue sapphire in 1911. The key to the process is that the alumina powder does not melt as it falls through the flame. Instead it forms a sinter cone on the pedestal. When the tip of that cone reaches the hottest part of the flame, the tip melts. Thus the crystal growth is started from a tiny point, ensuring minimal strain. Next, more oxygen
3713-1278: The causes of color in corundum extant can be found in Chapter ;4 of Ruby & Sapphire: A Gemologist's Guide (chapter authored by John Emmett, Emily Dubinsky and Richard Hughes). Sapphires are mined from alluvial deposits or from primary underground workings. Commercial mining locations for sapphire and ruby include (but are not limited to) the following countries: Afghanistan , Australia , Myanmar / Burma , Cambodia , China , Colombia , India , Kenya , Laos , Madagascar , Malawi , Nepal , Nigeria , Pakistan , Sri Lanka , Tajikistan , Tanzania , Thailand , United States, and Vietnam . Sapphires from different geographic locations may have different appearances or chemical-impurity concentrations, and tend to contain different types of microscopic inclusions. Because of this, sapphires can be divided into three broad categories: classic metamorphic, non-classic metamorphic or magmatic, and classic magmatic. Sapphires from certain locations, or of certain categories, may be more commercially appealing than others, particularly classic metamorphic sapphires from Kashmir, Burma, or Sri Lanka that have not been subjected to heat-treatment. The Logan sapphire ,
3792-459: The center of the star near the top of the dome. Occasionally, twelve-rayed stars are found, typically because two different sets of inclusions are found within the same stone, such as a combination of fine needles of rutile with small platelets of hematite ; the first results in a whitish star and the second results in a golden-colored star. During crystallization, the two types of inclusions become preferentially oriented in different directions within
3871-537: The chemical homogeneity of emeralds from the same mining location and the statistical differences that exist between emeralds from different mining locations, including those between the three locations: Muzo, Coscuez, and Chivor, in Colombia, South America. Both hydrothermal and flux-growth synthetics have been produced, and a method has been developed for producing an emerald overgrowth on colorless beryl . The first commercially successful emerald synthesis process
3950-409: The color penetration is far greater than with titanium diffusion. In some cases, it may penetrate the entire stone. Beryllium-diffused orange sapphires may be difficult to detect, requiring advanced chemical analysis by gemological labs ( e.g. , Gübelin, SSEF , GIA , American Gemological Laboratories (AGL), Lotus Gemology . According to United States Federal Trade Commission guidelines, disclosure
4029-470: The crystal, thereby forming two six-rayed stars that are superimposed upon each other to form a twelve-rayed star. Misshapen stars or 12-rayed stars may also form as a result of twinning . The inclusions can alternatively produce a cat's eye effect if the girdle plane of the cabochon is oriented parallel to the crystal's c-axis rather than perpendicular to it. To get a cat's eye, the planes of exsolved inclusions must be extremely uniform and tightly packed. If
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#17327768956574108-690: The deliberate addition of certain specific impurities (e.g. beryllium, titanium, iron, chromium or nickel, which are absorbed into the crystal structure of the sapphire) is also commonly performed, and this process can be known as "diffusion" in the gem trade. However, despite what the terms "heating only" and "diffusion" might suggest, both of these categories of treatment actually involve diffusion processes. The most complete description of corundum treatments extant can be found in Chapter 6 of Ruby & Sapphire: A Gemologist's Guide (chapter authored by John Emmett, Richard Hughes and Troy R. Douthit). In 1902,
4187-666: The discovery of the Colombian deposits. Today, only ruins remain in Egypt. Colombia is by far the world's largest producer of emeralds, constituting 50–95% of the world production, with the number depending on the year, source and grade. Emerald production in Colombia has increased drastically in the last decade, increasing by 78% from 2000 to 2010. The three main emerald mining areas in Colombia are Muzo , Coscuez, and Chivor . Rare "trapiche" emeralds are found in Colombia, distinguished by ray-like spokes of dark impurities. Zambia
4266-448: The dome is oriented in between these two directions, an off-center star will be visible, offset away from the high point of the dome. At 1404.49 carats, The Star of Adam is the largest known blue star sapphire. The gem was mined in the city of Ratnapura, southern Sri Lanka. The Black Star of Queensland , the second largest star sapphire in the world, weighs 733 carats . The Star of India mined in Sri Lanka and weighing 563.4 carats
4345-543: The flaws that are found in natural stones. The disadvantage of the Verneuil process is that the grown crystals have high internal strains. Many methods of manufacturing sapphire today are variations of the Czochralski process , which was invented in 1916 by Polish chemist Jan Czochralski . In this process, a tiny sapphire seed crystal is dipped into a crucible made of the precious metal iridium or molybdenum , containing molten alumina, and then slowly withdrawn upward at
4424-436: The highest premium, although Burma, Sri Lanka, and Madagascar also produce large quantities of fine quality gems. The cost of natural sapphires varies depending on their color, clarity, size, cut , and overall quality. Sapphires that are completely untreated are worth far more than those that have been treated. Geographical origin also has a major impact on price. For most gems of one carat or more, an independent report from
4503-666: The largest faceted gem-quality blue sapphires in existence. Particolored sapphires (or bi-color sapphires) are those stones that exhibit two or more colors within a single stone. The desirability of particolored or bi-color sapphires is usually judged based on the zoning or location of their colors, the colors' saturation, and the contrast of their colors. Australia is the largest source of particolored sapphires; they are not commonly used in mainstream jewelry and remain relatively unknown. Particolored sapphires cannot be created synthetically and only occur naturally. Pink sapphires occur in shades from light to dark pink, and deepen in color as
4582-411: The latter term is a misnomer: synthetic color-change sapphires are, technically, not synthetic alexandrites but rather alexandrite simulants . This is because genuine alexandrite is a variety of chrysoberyl : not sapphire, but an entirely different mineral from corundum. Large rubies and sapphires of poor transparency are frequently used with suspect appraisals that vastly overstate their value. This
4661-629: The locale. Commonly, natural sapphires are cut and polished into gemstones and worn in jewelry . They also may be created synthetically in laboratories for industrial or decorative purposes in large crystal boules . Because of the remarkable hardness of sapphires – 9 on the Mohs scale (the third-hardest mineral, after diamond at 10 and moissanite at 9.5) – sapphires are also used in some non-ornamental applications, such as infrared optical components, high-durability windows , wristwatch crystals and movement bearings, and very thin electronic wafers , which are used as
4740-599: The mere presence of oil or polymers to constitute enhancement. Others may ignore traces of oil if the presence of the material does not improve the look of the gemstone. Emeralds in antiquity were mined in Ancient Egypt at locations on Mount Smaragdus since 1500 BC, and India and Austria since at least the 14th century AD. The Egyptian mines were exploited on an industrial scale by the Roman and Byzantine Empires, and later by Islamic conquerors. Mining in Egypt ceased with
4819-406: The most common secondary hues found in blue sapphires. The highest prices are paid for gems that are pure blue and of vivid saturation. Gems that are of lower saturation, or are too dark or too light in tone are of less value. However, color preferences are a personal taste. The 423-carat (84.6 g) Logan sapphire in the National Museum of Natural History , in Washington, D.C. , is one of
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#17327768956574898-445: The normal secondary hues found in emeralds. Only gems that are medium to dark in tone are considered emeralds; light-toned gems are known instead by the species name green beryl . The finest emeralds are approximately 75% tone on a scale where 0% tone is colorless and 100% is opaque black. In addition, a fine emerald will be saturated and have a hue that is bright (vivid). Gray is the normal saturation modifier or mask found in emeralds;
4977-475: The other ingredients to prevent nucleation and confine growth to the seed crystals. Growth occurs by a diffusion-reaction process, assisted by convection. The largest producer of hydrothermal emeralds today is Tairus, which has succeeded in synthesizing emeralds with chemical composition similar to emeralds in alkaline deposits in Colombia, and whose products are thus known as “Colombian created emeralds” or “Tairus created emeralds”. Luminescence in ultraviolet light
5056-419: The pores of the stone and allow the fracture-filling agent to be absorbed more effectively. The U.S. Federal Trade Commission requires the disclosure of this treatment when an oil-treated emerald is sold. The use of oil is traditional and largely accepted by the gem trade, although oil-treated emeralds are worth much less than untreated emeralds of similar quality. Untreated emeralds must also be accompanied by
5135-585: The quantity of chromium increases. The deeper the pink color, the higher their monetary value . In the United States, a minimum color saturation must be met to be called a ruby , otherwise the stone is referred to as a pink sapphire . Padparadscha is a delicate, light to medium toned, pink-orange to orange-pink hued corundum , originally found in Sri Lanka , but also found in deposits in Vietnam and parts of East Africa . Padparadscha sapphires are rare;
5214-522: The rarest of all is the totally natural variety, with no sign of artificial treatment. The name is derived from the Sanskrit padma ranga (padma = lotus; ranga = color), a color akin to the lotus flower ( Nelumbo nucifera ). Among the fancy (non-blue) sapphires, natural padparadscha fetch the highest prices. Since 2001, more sapphires of this color have appeared on the market as a result of artificial lattice diffusion of beryllium. A star sapphire
5293-458: The rate of 1 mm per month, a typical seven-month growth run produces emerald crystals 7 mm thick. Hydrothermal synthetic emeralds have been attributed to IG Farben , Nacken, Tairus , and others, but the first satisfactory commercial product was that of Johann Lechleitner of Innsbruck , Austria, which appeared on the market in the 1960s. These stones were initially sold under the names "Emerita" and "Symeralds", and they were grown as
5372-463: The same geographical settings, but they generally have different geological formations. For example, both ruby and sapphire are found in Myanmar's Mogok Stone Tract, but the rubies form in marble, while the sapphire forms in granitic pegmatites or corundum syenites. Every sapphire mine produces a wide range of quality, and origin is not a guarantee of quality. For sapphire, Jammu and Kashmir receives
5451-428: The same term This disambiguation page lists articles about distinct geographical locations with the same name. If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=Esmeraldas&oldid=1170658238 " Category : Place name disambiguation pages Hidden categories: Short description
5530-405: The term emerald was first used in the 14th century. Emeralds, like all colored gemstones , are graded using four basic parameters known as "the four C s": color , clarity, cut and carat weight . Normally, in grading colored gemstones, color is by far the most important criterion. However, in the grading of emeralds, clarity is considered a close second. A fine emerald must possess not only
5609-412: The transfer of an electron from one transition-metal ion to another via the conduction or valence band . The iron can take the form Fe or Fe , while titanium generally takes the form Ti . If Fe and Ti ions are substituted for Al , localized areas of charge imbalance are created. An electron transfer from Fe and Ti can cause a change in the valence state of both. Because of the valence change, there
5688-506: The value of a sapphire, and most corundum of Kashmir origin can be readily identified by its characteristic silky appearance and exceptional hue. The unique blue appears lustrous under any kind of light, unlike non-Kashmir sapphires which may appear purplish or grayish in comparison. Sotheby's has been in the forefront overseeing record-breaking sales of Kashmir sapphires worldwide. In October 2014, Sotheby's Hong Kong achieved consecutive per-carat price records for Kashmir sapphires – first with
5767-445: The visible spectrum. This is an absorption band in the yellow (~590 nm), along with valleys of transmission in the blue-green and red. Thus the color one sees depends on the spectral composition of the light source. Daylight is relatively balanced in its spectral power distribution (SPD) and since the human eye is most sensitive to green light, the balance is tipped to the green side. However incandescent light (including candle light)
5846-416: The year 2000, beryllium diffused "padparadscha" colored sapphires entered the market. Typically beryllium is diffused into a sapphire under very high heat, just below the melting point of the sapphire. Initially ( c. 2000 ) orange sapphires were created, although now the process has been advanced and many colors of sapphire are often treated with beryllium. Due to the small size of the beryllium ion,
5925-490: Was named " Serendipity Sapphire ". A rare variety of natural sapphire, known as color-change sapphire, exhibits different colors in different light. Color change sapphires are blue in outdoor light and purple under incandescent indoor light, or green to gray-green in daylight and pink to reddish-violet in incandescent light. Color-change sapphires come from a variety of locations, including Madagascar , Myanmar , Sri Lanka and Tanzania . Two types exist. The first features
6004-550: Was not commonly disclosed; by the late 1980s, heat treatment became a major issue. At that time, much of all the world's sapphires were being heated to enhance their natural color. Intergem's marketing of guaranteed untreated Yogos set them against many in the gem industry. This issue appeared as a front-page story in The Wall Street Journal on 29 August 1984 in an article by Bill Richards, Carats and Schticks: Sapphire Marketer Upsets The Gem Industry . However,
6083-613: Was practically abandoned just a few years later because of the difficulties in recovering sapphires in their bedrock. In North America , sapphires have been mined mostly from deposits in Montana : facies along the Missouri River near Helena, Montana , Dry Cottonwood Creek near Deer Lodge, Montana , and Rock Creek near Philipsburg, Montana . Fine blue Yogo sapphires are found at Yogo Gulch west of Lewistown, Montana . A few gem-grade sapphires and rubies have also been found in
6162-419: Was that of Carroll Chatham , likely involving a lithium vanadate flux process, as Chatham's emeralds do not have any water and contain traces of vanadate, molybdenum and vanadium. The other large producer of flux emeralds was Pierre Gilson Sr., whose products have been on the market since 1964. Gilson's emeralds are usually grown on natural colorless beryl seeds, which are coated on both sides. Growth occurs at
6241-672: Was the case of the "Life and Pride of America Star Sapphire". Circa 1985, Roy Whetstine claimed to have bought the 1905-ct stone for $ 10 at the Tucson gem show, but a reporter discovered that L.A. Ward of Fallbrook, California, who appraised it at the price of $ 1200/ct, had appraised another stone of the exact same weight several years before Whetstine claimed to have found it. Bangkok-based Lotus Gemology maintains an updated listing of world auction records of ruby, sapphire, and spinel . As of November 2019, no sapphire has ever sold at auction for more than $ 17,295,796. Rubies are corundum with
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