Ammolite
Unprocessed sample of ammolite, a "dragon skin" pattern is apparent
General
Category	fossilized, mineralized Ammonite shell
Chemical formula	variable, often aragonite, calcite, pyrite, silica and others[1]
Identification
Color	Gray to brown, sometimes with iridescent colors.[1]
Fracture	uneven to granular[1]
Mohs Scale hardness	variable[1]
Luster	greasy to dull[1]
Polish luster	vitreous[1]
Refractive index	usually 1.52 - 1.68 (varies with mineral content)[1]
Optical Properties	anomalous aggregate reaction[1]
Birefringence	usually 1.55 (varies with mineral content)[1]
Pleochroism	none[1]
Ultraviolet fluorescence	variable[1]
Specific gravity	usually about 2.70 (varies with mineral content)[1]

Ammolite is a rare and valuable opal-like organic gemstone found primarily along the eastern slopes of the Rocky Mountains of the United States and Canada. It is made of the fossilized shells of ammonites, which in turn are composed primarily of aragonite, the same mineral that makes up nacreous pearls. It is one of the three biogenic gemstones, the other two being amber and pearl.¹ In 1981, ammolite was given official gemstone status by the World Jewellery Confederation, the same year commercial mining of ammolite began. In 2004 it was designated the official gemstone of the Province of Alberta.^[2] Image File history File links An unprocessed sample of ammolite, photographed wet and in natural light to simulate the effects of polishing. ... For other uses, see Ammonite (disambiguation). ... This article or section does not cite any references or sources. ... Aragonite Aragonite is a polymorph of the mineral calcite, both having the chemical composition CaCO3. ... Doubly refracting Calcite from Iceberg claim, Dixon, New Mexico. ... The mineral pyrite, or iron pyrite, is iron sulfide, FeS2. ... The chemical compound silicon dioxide, also known as silica, is the oxide of silicon, chemical formula SiO2. ... For fractures in geologic formations, see Rock fracture. ... Mohs scale of mineral hardness characterizes the scratch resistance of various minerals through the ability of a harder material to scratch a softer. ... Lustre (American English: luster) is a description of the way light interacts with the surface of a crystal, rock or mineral. ... The refractive index (or index of refraction) of a medium is a measure for how much the speed of light (or other waves such as sound waves) is reduced inside the medium. ... A calcite crystal laid upon a paper with some letters showing the double refraction Birefringence, or double refraction, is the decomposition of a ray of light into two rays (the ordinary ray and the extraordinary ray) when it passes through certain types of material, such as calcite crystals, depending on... Pleochroism is an optical phenomenon in which grains of a rock appear to be different colors when observed at different angles,under a petrographic microscope. ... Fluorescence induced by exposure to ultraviolet light in vials containing various sized Cadmium selenide (CdSe) quantum dots. ... Relative density (also known as specific gravity) is a measure of the density of a material. ... For other OPAL articles, see Opal (disambiguation). ... A selection of gemstone pebbles made by tumbling rough rock with abrasive grit, in a rotating drum. ... For individual mountains named Rocky Mountain, see Rocky Mountain (disambiguation). ... For other uses, see Fossil (disambiguation). ... For other uses, see Ammonite (disambiguation). ... Aragonite Aragonite is a polymorph of the mineral calcite, both having the chemical composition CaCO3. ... A mineral is a naturally occurring substance formed through geological processes that has a characteristic chemical composition, a highly ordered atomic structure and specific physical properties. ... Nacre, also known as mother of pearl, is a naturally-occurring organic-inorganic composite. ... Freshadama grade cultured freshwater pearls. ... A biogenic substance is a substance produced by natural processes. ... This article or section is in need of attention from an expert on the subject. ... Freshadama grade cultured freshwater pearls. ... The CIBJO (Confédération International de la Bijouterie, Joaillerie, Orfèvrerie des Diamantes, Perles et Pierres), also known as the World Jewellery Confederation, is an international confederation of jewellery, gemstone, horology, and silverware trade organisations. ... Regions Political culture Foreign relations Other countriesAtlas  Politics Portal      Canada is a federation which consists of ten provinces that, with three territories, make up the worlds second largest country in total area. ... Motto: Fortis et liber(Latin) Strong and free Capital Edmonton Largest city Calgary Official languages English (see below) Government - Lieutenant-Governor Norman Kwong - Premier Ed Stelmach (PC) Federal representation in Canadian Parliament - House seats 28 - Senate seats 6 Confederation September 1, 1905 (split from Northwest Territories) (8th [Province]) Area Ranked...

Ammolite is also known as aapoak (Kainah for "small, crawling stone"), gem ammonite, calcentine, and korite. The latter is a trade name given to the gemstone by the Alberta-based mining company Korite International, the first and largest commercial producer of ammolite. The Kainai (or Kainah, Kainaiwa) are a First Nation located in southern Alberta, Canada. ... Korite International is the largest commercial producer of ammolite. ...

Properties

The chemical composition of ammolite is variable, and aside from aragonite may include calcite, silica, pyrite, or other minerals. The shell itself may contain a number of trace elements, including: aluminium; barium; chromium; copper; iron; magnesium; manganese; strontium; titanium; and vanadium. Its crystallography is orthorhombic. Its hardness is 4.5–5.5, quite soft for a gemstone, and its specific gravity is 2.60–2.85. The refractive index of Canadian material (as measured via sodium light, 589.3 nm) is as follows: α 1.522; β 1.672–1.673; γ 1.676–1.679; biaxial negative. Under ultraviolet light, ammolite may fluoresce a mustard yellow. This article does not cite any references or sources. ... Doubly refracting Calcite from Iceberg claim, Dixon, New Mexico. ... The chemical compound silicon dioxide, also known as silica, is the oxide of silicon, chemical formula SiO2. ... The mineral pyrite, or iron pyrite, is iron sulfide, FeS2. ... General Name, symbol, number aluminium, Al, 13 Chemical series poor metals Group, period, block 13, 3, p Appearance silvery Standard atomic weight 26. ... General Name, Symbol, Number barium2, Ba, 56 Chemical series alkaline earth metals Group, Period, Block 2, 6, s Appearance silvery white Standard atomic weight 137. ... General Name, symbol, number chromium, Cr, 24 Chemical series transition metals Group, period, block 6, 4, d Appearance silvery metallic Standard atomic weight 51. ... For other uses, see Copper (disambiguation). ... General Name, symbol, number iron, Fe, 26 Chemical series transition metals Group, period, block 8, 4, d Appearance lustrous metallic with a grayish tinge Standard atomic weight 55. ... General Name, symbol, number magnesium, Mg, 12 Chemical series alkaline earth metals Group, period, block 2, 3, s Appearance silvery white solid at room temp Standard atomic weight 24. ... General Name, Symbol, Number manganese, Mn, 25 Chemical series transition metals Group, Period, Block 7, 4, d Appearance silvery metallic Standard atomic weight 54. ... General Name, Symbol, Number strontium, Sr, 38 Chemical series alkaline earth metals Group, Period, Block 2, 5, s Appearance silvery white metallic Standard atomic weight 87. ... General Name, symbol, number titanium, Ti, 22 Chemical series transition metals Group, period, block 4, 4, d Appearance silvery metallic Standard atomic weight 47. ... General Name, symbol, number vanadium, V, 23 Chemical series transition metals Group, period, block 5, 4, d Appearance silver-grey metal Standard atomic weight 50. ... Crystallography (from the Greek words crystallon = cold drop / frozen drop, with its meaning extending to all solids with some degree of transparency, and graphein = write) is the experimental science of determining the arrangement of atoms in solids. ... This article or section does not cite any references or sources. ... Relative density (also known as specific gravity) is a measure of the density of a material. ... The refractive index (or index of refraction) of a medium is a measure for how much the speed of light (or other waves such as sound waves) is reduced inside the medium. ... For sodium in the diet, see Edible salt. ... “UV” redirects here. ... Fluorescence induced by exposure to ultraviolet light in vials containing various sized Cadmium selenide (CdSe) quantum dots. ...

An iridescent opal-like play of color is shown in fine specimens, mostly in shades of green and red; all the spectral colors are possible, however. The iridescence is due to the microstructure of the aragonite: unlike most other gems, whose colors come from light absorption, the iridescent color of ammolite comes from interference with the light that rebounds from stacked layers of thin platelets that make up the aragonite. The thicker the layers, the more reds and greens are produced; the thinner the layers, the more blues and violets predominate. Reds and greens are the most commonly seen colors, owing to the greater fragility of the finer layers responsible for the blues. When freshly quarried, these colors are not especially dramatic; the material requires polishing and possibly other treatments in order to reveal the colors' full potential. The iridescence of the Blue Morpho butterfly wings. ... A spectral color is a color that is evoked by the optical spectrum; every wavelength of light yields a different spectral color, in a continuous spectrum. ... Interference of two circular waves - Wavelength (decreasing bottom to top) and Wave centers distance (increasing to the right). ...

The ammolite itself is actually a very thin sheet, ca. 0.5–0.8 millimeters (0.02–0.03 inches) in thickness. Rarely is ammolite without its matrix, which is typically a grey to brown shale, chalky clay, or limestone. So-called "frost shattering" is common; exposed to the elements and compressed by sediments, the thin ammolite tends to crack and flake; prolonged exposure to sunlight can also lead to bleaching. The cracking results in a tessellated appearance, sometimes described as a "dragon skin" or "stained glass window" pattern. Ammolite mined from deeper deposits may be entirely smooth or with a rippled surface. Occasionally a complete ammonite shell is recovered with its structure well-preserved: fine, convoluted lines delineate the shell chambers, and the overall shape is suggestive of a nautilus. While these shells may be as large as 90 centimeters (35.5 inches) in diameter, the iridescent ammonites (as opposed to the pyritized variety) are typically much smaller. Most fossilized shells have had their aragonite pseudomorphously replaced by calcite or pyrite, making the presence of ammolite particularly uncommon. ‹ The template below (Unit of length) is being considered for deletion. ... Shale Shale is a fine-grained sedimentary rock whose original constituents were clays or muds. ... The Gay Head cliffs in Marthas Vineyard are made almost entirely of clay. ... -1... It has been suggested that European dragon be merged into this article or section. ... Strictly speaking, stained glass is glass that has been painted with silver stain and then fired. ... Genera Allonautilus Nautilus Nautilus (from Greek ναυτίλος, sailor) is the common name of any marine creatures of the cephalopod family Nautilidae, the sole family of the suborder Nautilina. ... In geology, a pseudomorph is a mineral compound resulting from a substitution process in which the appearance and dimensions remain constant, but the mineral which makes up the chief component of the compound is replaced by another. ...

Formation, occurrence, and extraction

An iridescent ammonite from Madagascar

Map of North America highlighting the shallow inland sea present during the mid-Cretaceous period.

Ammolite comes from the fossil shells of the Upper Cretaceous disk-shaped ammonites Placenticeras meeki and Placenticeras intercalare, and (to a lesser degree) the cylindrical baculite Baculites compressus. Ammonites were cephalopods, or squid-like creatures, that thrived in tropical seas until becoming extinct along with the dinosaurs at the end of the Mesozoic era. Download high resolution version (1276x1366, 252 KB) Wikipedia does not have an article with this exact name. ... Download high resolution version (1276x1366, 252 KB) Wikipedia does not have an article with this exact name. ... Image File history File links File links The following pages link to this file: Western Interior Seaway Geology of the Grand Teton area Ammolite ... Image File history File links File links The following pages link to this file: Western Interior Seaway Geology of the Grand Teton area Ammolite ... North America North America is a continent[1] in the Earths northern hemisphere and (chiefly) western hemisphere. ... // The Cretaceous Period is one of the major divisions of the geologic timescale, reaching from the end of the Jurassic Period (i. ... // The Cretaceous Period is one of the major divisions of the geologic timescale, reaching from the end of the Jurassic Period (i. ... Species all extinct Baculites (walking stick rock) is a genus of extinct marine animals in the phylum Mollusca and class Cephalopoda. ... Orders Subclass Nautiloidea †Plectronocerida †Ellesmerocerida †Actinocerida †Pseudorthocerida †Endocerida †Tarphycerida †Oncocerida †Discosorida Nautilida †Orthocerida †Ascocerida †Bactritida Subclass †Ammonoidea †Goniatitida †Ceratitida †Ammonitida Subclass Coleoidea †Belemnoidea †Aulacocerida †Belemnitida †Hematitida †Phragmoteuthida Neocoleoidea (most living cephalopods) ?†Boletzkyida Sepiida Sepiolida Spirulida Teuthida Octopoda Vampyromorphida The cephalopods (Greek plural (kephalópoda); head-foot) are the mollusk class... Suborders †Plesioteuthididae (incertae sedis) Myopsina Oegopsina Squid are a large, diverse group of marine cephalopods. ... The Dodo, shown here in a 1651 illustration by Jan Savery, is an often-cited[1] example of modern extinction. ... Orders & Suborders Saurischia Sauropodomorpha Theropoda Ornithischia Thyreophora Ornithopoda Marginocephalia Dinosaurs were vertebrate animals that dominated the terrestrial ecosystem for over 160 million years, first appearing approximately 230 million years ago. ... The Mesozoic Era is one of three geologic eras of the Phanerozoic eon. ...

The ammonites that form ammolite inhabited a prehistoric, inland subtropical sea that bordered the Rocky Mountains—this area is known today as the Cretaceous or Western Interior Seaway. As the seas receded, the ammonites were buried and crushed by layers of bentonite sediment. This sediment preserved the aragonite of their shelled remains, preventing it from converting to calcite. Through diagenesis, the shells were impregnated by trace elements present in these sediments, the most common of these being iron and magnesium, the former of which accounts for the predominance of the green colors. Western Interior Seaway during the mid-Cretaceous, about 100 million years before the present The Western Interior Seaway, also called the Cretaceous Seaway, the Niobraran Sea, and the North American Inland Sea, was a huge inland sea that split the continent of North America into two halves during most of... Bentonite - USGS Bentonite is an absorbent aluminium phyllosilicate generally impure clay consisting mostly of montmorillonite, (Na,Ca)0. ... This article or section cites very few or no references or sources. ... Doubly refracting Calcite from Iceberg claim, Dixon, New Mexico. ... In geology and oceanography, diagenesis is any chemical, physical, or biological change undergone by a sediment after its initial deposition and during and after its lithification, exclusive of surface alteration (weathering) and metamorphism. ...

Korite International's mechanized mining operations are fairly basic, involving the excavation of shallow pits with backhoes.

Significant deposits of gem-quality ammolite are only found in the Bearpaw formation that extends from Alberta to Saskatchewan in Canada and south to Montana in the USA. The best grade of gem quality ammolite is along high energy river systems on the eastern slopes of the Rockies in southern Alberta. Most commercial mining operations have been conducted along the banks of the St. Mary River, in an area south of and between the town of Magrath and the city of Lethbridge. Roughly half of all ammolite deposits are contained within the Kainah (Kainaiwa) reserve, and its inhabitants play a major role in ammolite mining. Since its founding in 1979, Korite International has operated primarily within the reservation. The company maintains an agreement with the Kainah (Blood) tribe, with Korite International paying the tribe royalties based on how much land the company has mined. Image File history File links File links The following pages link to this file: Ammolite ... Image File history File links File links The following pages link to this file: Ammolite ... Motto: Multis E Gentibus Vires (Latin: The Strength of Many Peoples) Capital Regina Largest city Saskatoon Official languages English Government - Lieutenant-Governor Gordon Barnhart - Premier Lorne Calvert (NDP) Federal representation in Canadian Parliament - House seats 14 - Senate seats 6 Confederation September 1, 1905 (Split from NWT) (9th (province)) Area  Ranked... Official language(s) English Capital Helena Largest city Billings Area  Ranked 4th  - Total 147,165 sq mi (381,156 km²)  - Width 255 miles (410 km)  - Length 630 miles (1,015 km)  - % water 1  - Latitude 44°26N to 49°N  - Longitude 104°2W to 116°2W Population  Ranked... The Saint Mary River is a tributary of the Saskatchewan River. ... Magrath, a city in the province of Alberta, Canada, has a population of about 1,700 people. ... Lethbridge is a city in the province of Alberta, Canada. ... The Kainai (or Kainah, Kainaiwa) are a First Nation located in southern Alberta, Canada. ... In Canada, an Indian reserve is specified by the Indian Act as a tract of land, the legal title to which is vested in Her Majesty, that has been set apart by Her Majesty for the use and benefit of a band. ...

Another view of Korite International's open-pit mining operations in Alberta, Canada.

Commercial extraction is mechanized but fairly basic: shallow open pits are dug with a backhoe and the excavated material is screened for its potential gem contents. The pits are further examined by hand, and commercial production is supplemented by independent persons who sell their surface-picked findings to Korite International and several other producers. Approximately 50% of the ammolite mined is suitable for jewelry. Image:Ammolite mining2. ... Image:Ammolite mining2. ... El Chino, located near Silver City, New Mexico, is an open-pit copper mine Open-pit mining, or opencast mining, refers to a method of extracting rock or minerals from the earth by their removal from an open pit or borrow. ... It has been suggested that Backhoe fade be merged into this article or section. ...

The ammolite deposits are stratified into several layers: the shallowest of these layers, named the "K Zone", lies some 15 meters below the surface and extends 30 meters down. The ammolite within this layer is covered by siderite concretions and is usually cracked—this is the crush material. It is the most common and (generally speaking) the least valuable of ammolite. Beginning twenty meters below the crush material is the "Blue Zone"; ammolite from this zone, which extends 65 meters, is usually compressed with a thin layer of pyrite rather than siderite concretions. This is the sheet material; due to its depth it is rarely mined. It is also much less fractured, and therefore the more valuable type of ammolite. Siderite is also the name of a type of iron meteorite. ... 1. ... The mineral pyrite, or iron pyrite, is iron sulfide, FeS2. ... Siderite is also the name of a type of iron meteorite. ...

As of 2003, Korite International had only mined 30 acres (120,000 m²) of the Kainah deposit. As part of their agreement with the tribe, the company must refill areas once exhausted, and ensure the environment is not adversely affected. Korite International's operations net the Kainah tribe approximately CAD $150,000–200,000 per year. The company employs over 60 people (many of them Kainah), and accounts for approximately 90% of world gem ammolite production. Prospectors who wish to mine ammolite deposits on Crown land must apply to the Alberta Department of Energy for a lease. These leases are not regularly offered; as of 2004, there was a CAD $625 application fee, with an annual rental fee of CAD $3.50 per hectare[1]. 2003 is a common year starting on Wednesday of the Gregorian calendar, and also: The International Year of Freshwater The European Disability Year Events January events January 1 Luíz Inácio Lula Da Silva becomes the 37th President of Brazil. ... An acre is the name of a unit of area in a number of different systems, including Imperial units and United States customary units. ... It has been suggested that this article or section be merged with Loonie. ... This article or section is in need of attention from an expert on the subject. ... Crown land is a designated area belonging to the Crown, the equivalent of an entailed estate that passed with the monarchy and could not be alienated from it. ... A hectare (symbol ha) is a unit of area, equal to 10 000 square metres, commonly used for measuring land area. ...

Gemstone quality

The quality of gem ammolite is communicated via a letter grade system, from best to least best: AA; A+; A; and A-. However, this system is not yet standardized and some vendors may use their own systems. The grade and therefore the value of an ammolite gemstone is determined by the following criteria:

The number of primary colors 

A large array of color is displayed in ammolite, including all the spectral colors found in nature. Red and green are far more common than blue or purple due to the latter's fragility (see properties). There are also certain hues, like crimson or violet or gold, which are derived from a combination of the primary colors, that are the rarest and in highest demand. The most valuable grades have roughly equal portions of three or more primary colors or 1–2 bright and even colors, with the lowest grades having one comparatively dull color predominant.

The way the colors play (chromatic shift and rotational range) 

Chromatic shift is how the colors vary with the angle of viewing and the angle of light striking the gemstone; in higher grades this variation is almost prismatic in its scope, while lower grades show very little variation. Rotational range is how far the specimen can be turned while maintaining its play of color; the best rotate 360 degrees uncompromised, while lesser stones may exhibit highly directional colors that are only visible within a narrow rotational range, down to 90° or less. Intermediate grades have ranges of 240–180°.

Brightness of colors (iridescence) 

The brightness of colors and their iridescence is essentially dependent on how well-preserved the nacreous shell is, and how fine and orderly the layers of aragonite are. The quality of the polish is also a factor. The "dragon skin" cracking usually hinders its value; the most prized ammolite is the sheet type (see formation) and has broad, uninterrupted swathes of color similar to the "broad flash" category of opal. The matrix is not visible in finer grades, and there should be no foreign minerals breaking up or diminishing the iridescence.

The thickness of the ammolite layer is also an important factor: after polishing, the ammolite is only 0.1–0.3 millimeters thick. The rarest and most valuable are thick enough to stand alone, with only a thin portion of its original matrix (not exceeding 1.5 mm); but the vast majority require some sort of supportive backing. Other treatments are also commonly undertaken; all other factors being equal, the less treatment an ammolite gem has received, the more valuable it is. Calibrated stones—that is, stones fashioned into standard dimensions that will fit most jewelry settings—may also command a higher price. The emission spectra of red, green, and blue phosphors that define the additive primary colors of a CRT color video display Primary colors, for humans, are sets of colors that can be combined to make a whole gamut of colors. ... The iridescence of the Blue Morpho butterfly wings. ... Fig. ... If a shaft of light entering a prism is sufficiently narrow, a spectrum results. ... The iridescence of the Blue Morpho butterfly wings. ...

Ammolite is considered the rarest organic gem material. It is soft and delicate, most often requiring special processing techniques known only to a few experts specializing in this commercial industry. In its rough state, ammolite is sold for USD $30 to 65 per carat (150 to 325 $/g). The United States dollar is the official currency of the United States. ... The carat is a unit of mass used for gems, and equals 200 milligrams or 3. ...

Treatments

Although fully mineralized and containing no water—and therefore not subject to dehydration and subsequent crazing as seen in opal—ammolite is often damaged due to environmental exposure. The thin, delicate sheets in which ammolite occurs are also problematic; for these reasons, most material is impregnated with a clear epoxy or other synthetic resin to stabilize the flake-prone ammolite prior to cutting. Although the tessellated cracking cannot be repaired, the epoxy prevents further flaking and helps protect the relatively soft surface from scratching. The impregnation process was developed over a number of years by Korite International in partnership with the Alberta Research Council. Impregnated and epoxy-coated ammolite first entered the market in 1989 and the treatment significantly increased the availability of the gem. Impact from a water drop causes an upward rebound jet surrounded by circular capillary waves. ... In chemistry, epoxy or polyepoxide is a thermosetting epoxide polymer that cures (polymerizes and crosslinks) when mixed with a catalyzing agent or hardener. Most common epoxy resins are produced from a reaction between epichlorohydrin and bisphenol-A. The first commercial attempts to prepare resins from epichlorohydrin occurred in 1927 in...

Because the ammolite layer is usually mere fractions of a millimeter in thickness, most ammolite gems are in fact composite stones: these usually take the form of two-part doublets, with the ammolite layer adhered to a dark backing material. This is usually the matrix or mother rock from which the ammolite was quarried; black onyx or glass could also be used as backing. In composites where the ammolite layer is exceptionally thin, a third component is used: this constitutes a triplet, with a durable and transparent convex topping piece. This cap may be either synthetic spinel, synthetic corundum, synthetic quartz, or in lower-end productions, glass. The convex cap acts as a lens and has the effect of enhancing the ammolite's iridescent display. Onyx is a cryptocrystalline form of quartz. ... Glass can be made transparent and flat, or into other shapes and colors as shown in this sphere from the Verrerie of Brehat in Brittany. ... The spinels are any of a class of minerals which crystallize in the isometric system with an octahedral habit. ... Corundum (from Tamil kurundam) is a crystalline form of aluminium oxide and one of the rock-forming minerals. ... Quartz (from German Quarz[1]) is the second most common mineral in the Earths continental crust. ... A lens. ...

The detection of these treated and composite stones is relatively simple via inspection with a loupe; however, certain jewelry setting styles—such as those with closed backs—can complicate things. A triplet can be identified by inspecting the stone in profile; the top of the stone can then be seen to be domed and transparent, with no play of color. If the dome is made of glass, bubbles, swirl marks, and scratches may be present; the harder synthetic materials are optically flawless. A magnifying glass A magnifying glass is a single convex lens which is used to produce a magnified image of an object. ...

Although the vast majority of commercial-grade ammolite has been treated in some way, a small fraction of production requires no treatment other than cutting and polishing. Ideally, any treatments should be disclosed at the time of sale.

Imitations

The iridescent flashes (labradorescence) of labradorite may lead to its confusion with ammolite by the unfamiliar, but the overall appearance is unconvincing as an imitation.

Ammolite is neither easily nor often imitated; however, a few materials have a passing resemblance that may deceive the unfamiliar. These include: labradorite (also known as spectrolite), an iridescent feldspar also of Canadian origin; and broad-flash black opal. Neither are convincing substitutes, and the latter is actually of greater value than ammolite. Indeed, ammolite is often used as an imitation of black opal. An even less convincing possibility is Slocum stone, a common glass-based imitation of opal. Blues and purples are much more pervasive in labradorite, and in both it and opal the play of color is seen to roll across the stone unlike the comparatively restricted play of color in ammolite. In Slocum stone, the play of color takes the form of tinsel-like patches. The visible structure is also considerably different; in the imitations, the body of the stone is transparent to translucent from certain angles, whereas ammolite is entirely opaque. Commons:Imagem:Labradorite detail. ... Commons:Imagem:Labradorite detail. ... Labradorite, a feldspar mineral, is a member of the plagioclase series. ... This article does not cite any references or sources. ... OPAL is also the name of one of the four detectors of the Large Electron-Positron Collider. ...

Gemologically speaking, ammolite can be grouped with the shell-based marbles. This group includes lumachella or "fire marble", a similarly iridescent marble composed of fossilized clam and snail shells. Found in Italy and Austria, lumachella is rarely if ever used in jewelry; rather, it is used as a decorative facing stone or in mosaics. The iridescence of lumachella is fragmentary and not nearly as brilliant as that of ammolite. Despite these differences, lumachella may be considered synonymous with ammolite in some circles. Gemology (gemmology outside the United States) is the science, art and profession of identifying and evaluating gemstones. ... Venus de Milo, front. ... Littleneck clams; the pictured mollusks are of the species Mercenaria mercenaria. ... The name snail applies to most members of the molluscan class Gastropoda that have coiled shells. ... Mosaic is the art of decoration with small pieces of colored glass, stone or other material. ...

The predominantly blue-green iridescent shell of abalone (or paua; genus Haliotis) is one last possible imitation. Abalone shell is inexpensive and plentiful owing to the commercial mariculture of these gastropods for their meat. The shell's structure is distinctive: sinuous bands of blue, green, and rose iridescence are delineated by dark brown lines of conchiolin, a proteinaceous material that holds the shell together. The luster of abalone shell is silky rather than the near vitreous luster of polished ammolite, and the colors of the two materials do not closely approximate. However, some abalone shell has been dyed and given a transparent cap of synthetic quartz, forming a doublet in the same fashion as ammolite. These doublets are perhaps the most deceptive, and have also been used to imitate opal. Under magnification most abalone doublets will show dye concentrated along certain areas and air bubbles trapped at the shell-quartz interface. Species Many, see species section. ... For other uses, see Genus (disambiguation). ... Species Many, see text Haliotis is a genus of abalone, the sole genus in the family Haliotidae. ... Mariculture is the cultivation of marine organisms for food, either in their natural environment or in seawater in ponds or raceways. ... Subclass Subclass Eogastropoda     Patellogastropoda Subclass Orthogastropoda   Superorder Cocculiniformia   Superorder Hot Vent Taxa     Neomphaolida   Superorder Vetigastropoda   Superorder Neritaemorphi     Neritopsina   Superorder Caenogastropoda     Architaenioglossa     Sorbeoconcha   Superorder Heterobranchia     Heterostropha     Opisthobranchia     Pulmonata The gastropods, or univalves, are the largest and most successful class of mollusks, with 60,000-75,000 species, and second largest class... Conchiolin (sometimes referred to as conchin) and perlucin are complex proteins which are secreted by a molluscs outer epithelium (the mantle). ... A representation of the 3D structure of myoglobin, showing coloured alpha helices. ... Lustre (American English: luster) is a description of the way light interacts with the surface of a crystal, rock or mineral. ... Look up dye in Wiktionary, the free dictionary. ...

Use in jewelry

Fine ammolite jewelry by Korite International. The ammolite gems are triplets, as evidenced by their convex profiles, and are set in 14 karat (58%) gold with diamond accents. Ammolite is best used in pendants, earrings, and brooches due to its fragility.

Compared to most other gems, ammolite has a rather scant history of use; it did not begin to garner interest in Western society until the 1970s after entering the market (to a limited degree) in 1969. The Blackfeet tribe know ammolite as iniskim, meaning "buffalo stone", and have long believed it to possess amuletic powers; specifically, the gem is believed to aid in the buffalo hunt, and to draw the buffalo within tracking distance. The Blackfeet also believe ammolite to possess healing powers and incorporate the gem into their medicine bundles for use in ceremonies. Image File history File links File links The following pages link to this file: Ammolite ... Image File history File links File links The following pages link to this file: Ammolite ... Carat is a measure of the purity of gold and platinum alloys. ... Sahpo Muxika, also known as Crowfoot, former Head Chief of the Blackfeet Nation The Piegan Blackfeet (Pikuni in Blackfoot) are a tribe of Native Americans based in Montana. ... Binomial name (Linnaeus, 1758) Subspecies B. b. ... An amulet from the Black Pullet grimoire An amulet (from Latin amuletum, meaning A means of protection) or a talisman (from Arabic tilasm, ultimately from Greek telesma or from the Greek word talein wich means to initiate into the mysteries. ... A medicine bundle is a wrapped package used by Native Americans for religious purposes. ...

In the late 1990s, practitioners of Feng Shui began to promote ammolite as an "influential" stone with what they believe is the power to enhance well-being and detoxify the body by improving its flow of energy or "chi". Named the "Seven Color Prosperity Stone", each color is believed by Feng Shui practitioners to influence the wearer in different and positive ways; a combination of ruby red, emerald green, and amber yellow is most sought after for this purpose, the colors being said to enhance growth, wisdom, and wealth, respectively. Fēng Shuǐ (風水 – literally, wind and water pronounced fung shuway), which may be more than 3000 years old, is the ancient practice of placement to achieve harmony with the environment. ... QI, standing for Quite Interesting, is a comedy panel game television quiz show created and produced by John Lloyd, hosted by Stephen Fry, and featuring regular panellist Alan Davies, who has appeared on every episode. ... This article does not cite any references or sources. ... This article or section does not cite its references or sources. ... This article or section is in need of attention from an expert on the subject. ...

Ammolite is usually fashioned into freeform cabochons and mounted in gold, with diamonds as accents. Due to its delicacy, ammolite is best reserved for use in pendants, earrings, and brooches; if used as a ring stone, ammolite should be given a hard protective cap, namely one of synthetic spinel as used in triplets. Whole polished ammonites of appropriately small size may also be mounted in jewelry. Nothing harsher than mild soap and warm water should be used to clean ammolite jewelry; ultrasonic cleaning should be avoided. A cabochon or cabouchon is a gemstone which has been shaped and polished as opposed to facetted. ... GOLD refers to one of the following: GOLD (IEEE) is an IEEE program designed to garner more student members at the university level (Graduates of the Last Decade). ... This article is about the gemstone. ... A pendant (from Old French) is a hanging object, generally attached to a necklace or an earring. ... An earring is a piece of jewelry that is worn on the ear. ... Aquamarine, platinum and diamond brooch/pendant worn by Mrs. ... Amber jewellery in the form of pendants Jewellery (also spelled jewelry, see spelling differences) is a personal ornament, such as a necklace, ring, or bracelet, made from jewels, precious metals or other substance. ... Ultrasound is a form of cyclic sound pressure with a frequency greater than the upper limit of human hearing, this limit being approximately 20 kilohertz (20,000 hertz). ...

Japan is the largest market for ammolite; this may be due to its use as an imitation of increasingly scarce black opal, or its aforementioned use in Feng Shui. Secondary markets include Canada, where it is used both by artisans who sell their creations to tourists of Banff National Park and in fine jewelry production; and the Southwest United States, where it is used by Zuni and other Native American craftspeople. An artisan, also called a craftsman,[1] is a skilled manual worker who uses tools and machinery in a particular craft. ... Moraine Lake, and the Valley of the Ten Peaks Banff National Park is Canadas oldest national park, established in 1885, in the Canadian Rockies. ... The Southwest region of the United States is drier than the adjoining Midwest in weather; the population is less dense and, with strong Spanish-American and Native American components, more ethnically varied than neighboring areas. ... The Zuni (also spelled Zuñi) or Ashiwi are a Native American tribe, one of the Pueblo peoples, most of whom live in the Pueblo of Zuñi on the Zuni River, a tributary of the Little Colorado River, in western New Mexico. ... Native Americans in the United States are the indigenous peoples from the regions of North America now encompassed by the continental United States, including parts of Alaska. ...

Notes

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Ammolite

Image File history File links No higher resolution available. ... Image File history File links Commons-logo. ... This article or section does not cite its references or sources. ... A sample of jet Jet is a geological material that is not considered a mineral in the true sense of the word, but rather, a mineraloid derived from decaying wood under extreme pressure, thus organic in origin. ... A piece of nacre Nacre, also known as mother of pearl, is an organic mixture of calcium carbonate (CaCO3) in the form of platy crystals of aragonite and conchiolin (a scleroprotein). ... Tortoiseshell is a material that was widely used in the 1960s and 70s to make things from combs, to sunglasses, to guitar picks. ...

References

The Gemological Institute of America, or GIA, is a non-profit institute dedicated to research and education in the field of gemology. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era. ... is the 201st day of the year (202nd in leap years) in the Gregorian calendar. ...