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Beryl ( ) is a
mineral In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid chemical compound with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form.John P. Rafferty, ed. (2 ...
composed of
beryllium Beryllium is a chemical element with the symbol Be and atomic number 4. It is a steel-gray, strong, lightweight and brittle alkaline earth metal. It is a divalent element that occurs naturally only in combination with other elements to form m ...
aluminium Aluminium (aluminum in American and Canadian English) is a chemical element with the symbol Al and atomic number 13. Aluminium has a density lower than those of other common metals, at approximately one third that of steel. I ...
silicate with the
chemical formula In chemistry, a chemical formula is a way of presenting information about the chemical proportions of atoms that constitute a particular chemical compound or molecule, using chemical element symbols, numbers, and sometimes also other symbol ...
Be3Al2Si6O18. Well-known varieties of beryl include emerald and aquamarine. Naturally occurring,
hexagonal In geometry, a hexagon (from Greek , , meaning "six", and , , meaning "corner, angle") is a six-sided polygon. The total of the internal angles of any simple (non-self-intersecting) hexagon is 720°. Regular hexagon A '' regular hexagon'' has ...
crystal A crystal or crystalline solid is a solid material whose constituents (such as atoms, molecules, or ions) are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions. In addition, macro ...
s of beryl can be up to several meters in size, but terminated crystals are relatively rare. Pure beryl is colorless, but it is frequently tinted by impurities; possible colors are green, blue, yellow, pink, and red (the rarest). It is an ore source of
beryllium Beryllium is a chemical element with the symbol Be and atomic number 4. It is a steel-gray, strong, lightweight and brittle alkaline earth metal. It is a divalent element that occurs naturally only in combination with other elements to form m ...
.


Etymology

The word ''beryl'' – enm, beril – is borrowed, via fro, beryl and la, beryllus, from
Ancient Greek Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic p ...
βήρυλλος ''bḗryllos'', which referred to a 'precious blue-green color-of-sea-water stone'; from
Prakrit The Prakrits (; sa, prākṛta; psu, 𑀧𑀸𑀉𑀤, ; pka, ) are a group of vernacular Middle Indo-Aryan languages that were used in the Indian subcontinent from around the 3rd century BCE to the 8th century CE. The term Prakrit is usu ...
''veruḷiya'', ''veḷuriya'' 'beryl' (compare the pseudo-
Sanskrit Sanskrit (; attributively , ; nominally , , ) is a classical language belonging to the Indo-Aryan branch of the Indo-European languages. It arose in South Asia after its predecessor languages had diffused there from the northwest in the late ...
ization वैडूर्य ''vaiḍūrya'' 'cat's eye; jewel; lapis lazuli', traditionally explained as '(brought) from (the city of) Vidūra'), which is ultimately of Dravidian origin, maybe from the name of Belur or ''Velur'', a town in
Karnataka Karnataka (; ISO: , , also known as Karunāḍu) is a state in the southwestern region of India. It was formed on 1 November 1956, with the passage of the States Reorganisation Act. Originally known as Mysore State , it was renamed ''Karnat ...
, southern
India India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the so ...
. The term was later adopted for the mineral beryl more exclusively. When the first
eyeglasses Glasses, also known as eyeglasses or spectacles, are vision eyewear, with lenses (clear or tinted) mounted in a frame that holds them in front of a person's eyes, typically utilizing a bridge over the nose and hinged arms (known as temples or ...
were constructed in 13th-century Italy, the lenses were made of beryl (or of
rock crystal Quartz is a hard, crystalline mineral composed of silica (silicon dioxide). The atoms are linked in a continuous framework of SiO4 silicon-oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical form ...
) as glass could not be made clear enough. Consequently, glasses were named ''Brillen'' in German (''bril'' in Dutch and ''briller'' in Danish).


Deposits

Beryl is a common mineral, and it is widely distributed in nature. It found most commonly in
granitic A granitoid is a generic term for a diverse category of coarse-grained igneous rocks that consist predominantly of quartz, plagioclase, and alkali feldspar. Granitoids range from plagioclase-rich tonalites to alkali-rich syenites and from quartz- ...
pegmatites, but also occurs in mica
schist Schist ( ) is a medium-grained metamorphic rock showing pronounced schistosity. This means that the rock is composed of mineral grains easily seen with a low-power hand lens, oriented in such a way that the rock is easily split into thin flakes ...
s, such as those of the
Ural Mountains The Ural Mountains ( ; rus, Ура́льские го́ры, r=Uralskiye gory, p=ʊˈralʲskʲɪjə ˈɡorɨ; ba, Урал тауҙары) or simply the Urals, are a mountain range that runs approximately from north to south through western ...
, and in
limestone Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms whe ...
in Colombia. It is less common in ordinary granite and is only infrequently found in
nepheline syenite Nepheline syenite is a holocrystalline plutonic rock that consists largely of nepheline and alkali feldspar. The rocks are mostly pale colored, grey or pink, and in general appearance they are not unlike granites, but dark green varieties are al ...
. Beryl is often associated with
tin Tin is a chemical element with the symbol Sn (from la, stannum) and atomic number 50. Tin is a silvery-coloured metal. Tin is soft enough to be cut with little force and a bar of tin can be bent by hand with little effort. When bent, t ...
and
tungsten Tungsten, or wolfram, is a chemical element with the symbol W and atomic number 74. Tungsten is a rare metal found naturally on Earth almost exclusively as compounds with other elements. It was identified as a new element in 1781 and first isol ...
ore bodies formed as high-temperature hydrothermal veins. In granitic pegmatites, beryl is found in association with
quartz Quartz is a hard, crystalline mineral composed of silica ( silicon dioxide). The atoms are linked in a continuous framework of SiO4 silicon-oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical ...
,
potassium feldspar Potassium feldspar refers to a number of minerals in the feldspar group, and containing potassium: *Orthoclase ( endmember formula K Al Si3 O8), an important tectosilicate mineral that forms igneous rock *Microcline, chemically the same as orthocla ...
,
albite Albite is a plagioclase feldspar mineral. It is the sodium endmember of the plagioclase solid solution series. It represents a plagioclase with less than 10% anorthite content. The pure albite endmember has the formula . It is a tectosilicate ...
,
muscovite Muscovite (also known as common mica, isinglass, or potash mica) is a hydrated phyllosilicate mineral of aluminium and potassium with formula K Al2(Al Si3 O10)( F,O H)2, or ( KF)2( Al2O3)3( SiO2)6( H2O). It has a highly perfect basal cleavag ...
, biotite, and
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 te ...
. Beryl is sometimes found in
metasomatic Metasomatism (from the Greek μετά ''metá'' "change" and σῶμα ''sôma'' "body") is the chemical alteration of a rock by hydrothermal and other fluids. It is the replacement of one rock by another of different mineralogical and chemical com ...
contacts of igneous intrusions with
gneiss Gneiss ( ) is a common and widely distributed type of metamorphic rock. It is formed by high-temperature and high-pressure metamorphic processes acting on formations composed of igneous or sedimentary rocks. Gneiss forms at higher temperatures a ...
, schist, or
carbonate rock Carbonate rocks are a class of sedimentary rocks composed primarily of carbonate minerals. The two major types are limestone, which is composed of calcite or aragonite (different crystal forms of CaCO3), and dolomite rock (also known as dolosto ...
s. Common beryl, mined as beryllium ore, is found in small deposits in many countries, but the main producers are Russia, Brazil, and the United States.
New England New England is a region comprising six states in the Northeastern United States: Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, and Vermont. It is bordered by the state of New York (state), New York to the west and by the Can ...
's
pegmatites A pegmatite is an igneous rock showing a very coarse texture, with large interlocking crystals usually greater in size than and sometimes greater than . Most pegmatites are composed of quartz, feldspar, and mica, having a similar silicic co ...
have produced some of the largest beryls found, including one massive crystal from the Bumpus Quarry in
Albany, Maine South Oxford is an unorganized territory located in Oxford County, Maine, United States. The population was 591 at the 2020 census. The unorganized territory encompasses the areas designated under state law as Albany Township, Mason Township, a ...
with dimensions with a mass of around 18 metric tons; it is New Hampshire's state mineral. , the world's largest known naturally occurring crystal of any mineral is a crystal of beryl from Malakialina, Madagascar, long and in diameter, and weighing .


Crystal habit and structure

Beryl belongs to the
hexagonal crystal system In crystallography, the hexagonal crystal family is one of the six crystal families, which includes two crystal systems (hexagonal and trigonal) and two lattice systems (hexagonal and rhombohedral). While commonly confused, the trigonal crysta ...
. Normally beryl forms hexagonal columns but can also occur in massive habits. As a
cyclosilicate Silicate minerals are rock-forming minerals made up of silicate groups. They are the largest and most important class of minerals and make up approximately 90 percent of Earth's crust. In mineralogy, silica (silicon dioxide, ) is usually consid ...
beryl incorporates rings of silicate tetrahedra of that are arranged in columns along the  axis and as parallel layers perpendicular to the  axis, forming channels along the  axis. These channels permit a variety of ions, neutral atoms, and molecules to be incorporated into the crystal thus disrupting the overall charge of the crystal permitting further substitutions in
aluminium Aluminium (aluminum in American and Canadian English) is a chemical element with the symbol Al and atomic number 13. Aluminium has a density lower than those of other common metals, at approximately one third that of steel. I ...
,
silicon Silicon is a chemical element with the symbol Si and atomic number 14. It is a hard, brittle crystalline solid with a blue-grey metallic luster, and is a tetravalent metalloid and semiconductor. It is a member of group 14 in the periodic ta ...
, and
beryllium Beryllium is a chemical element with the symbol Be and atomic number 4. It is a steel-gray, strong, lightweight and brittle alkaline earth metal. It is a divalent element that occurs naturally only in combination with other elements to form m ...
sites in the crystal structure. These impurities give rise to the variety of colors of beryl that can be found. Increasing alkali content within the silicate ring channels causes increases to the
refractive indices In optics, the refractive index (or refraction index) of an optical medium is a dimensionless number that gives the indication of the light bending ability of that medium. The refractive index determines how much the path of light is bent, or ...
and birefringence.


Human health impact

Beryl is a beryllium compound that is a known carcinogen with acute toxic effects leading to pneumonitis when inhaled. Care must thus be used when mining, handling, and refining these gems.


Varieties


Aquamarine and maxixe

Aquamarine (from la, aqua marina, " sea water") is a blue or cyan variety of beryl. It occurs at most localities which yield ordinary beryl. The gem-gravel placer deposits of Sri Lanka contain aquamarine. Green-yellow beryl, such as that occurring in Brazil, is sometimes called ''chrysolite aquamarine''. The deep blue version of aquamarine is called ''maxixe''. The pale blue color of aquamarine is attributed to Fe2+. Fe3+ ions produce golden-yellow color, and when both Fe2+ and Fe3+ are present, the color is a darker blue as in maxixe. Decoloration of maxixe by light or heat thus may be due to the charge transfer between Fe3+ and Fe2+. In the United States, aquamarines can be found at the summit of Mt. Antero in the
Sawatch Range The Sawatch Range or Saguache RangeThe place name "Saguache” is pronounced “Sawatch” . This name derives from the Ute language noun "''sawup''" meaning "sand dunes" and is spelled using the Spanish language version of this name "Saguac ...
in central Colorado, and in the New England and North Carolina pegmatites. Aquamarines are also present in the state of
Wyoming Wyoming () is a state in the Mountain West subregion of the Western United States. It is bordered by Montana to the north and northwest, South Dakota and Nebraska to the east, Idaho to the west, Utah to the southwest, and Colorado to the s ...
, aquamarine has been discovered in the
Big Horn Mountains The Bighorn Mountains ( cro, Basawaxaawúua, lit=our mountains or cro, Iisaxpúatahchee Isawaxaawúua, label=none, lit=bighorn sheep's mountains) are a mountain range in northern Wyoming and southern Montana in the United States, forming a nort ...
, near
Powder River Pass :''The Powder River Pass is also the name of a football play, taking place between Arkansas and Ole Miss in 1954.'' Powder River Pass (el. 9666 ft.) is a mountain pass in the Bighorn Mountains in Wyoming Wyoming () is a state in t ...
. Another location within the United States is the Sawtooth Range near
Stanley, Idaho Stanley is a town in the Sawtooth Valley in Custer County, Idaho, United States. The population was 116 at the 2020 census; up from 63 in 2010. The center of population of Idaho in 2000 was located in Stanley. History Fur trappers of the H ...
, although the minerals are within a wilderness area which prevents collecting. In Brazil, there are mines in the states of
Minas Gerais Minas Gerais () is a state in Southeastern Brazil. It ranks as the second most populous, the third by gross domestic product (GDP), and the fourth largest by area in the country. The state's capital and largest city, Belo Horizonte (literally ...
,
Espírito Santo Espírito Santo (, , ; ) is a state in southeastern Brazil. Its capital is Vitória, and its largest city is Serra. With an extensive coastline, the state hosts some of the country's main ports, and its beaches are significant tourist attra ...
, and
Bahia Bahia ( , , ; meaning "bay") is one of the 26 states of Brazil, located in the Northeast Region of the country. It is the fourth-largest Brazilian state by population (after São Paulo, Minas Gerais, and Rio de Janeiro) and the 5th-largest b ...
, and minorly in
Rio Grande do Norte Rio Grande do Norte (, , ) is one of the states of Brazil. It is located in the northeastern region of the country, forming the northeasternmost tip of the South American continent. The name literally translates as "Great Northern River", re ...
. The mines of Colombia, Madagascar, Russia,
Namibia Namibia (, ), officially the Republic of Namibia, is a country in Southern Africa. Its western border is the Atlantic Ocean. It shares land borders with Zambia and Angola to the north, Botswana to the east and South Africa to the south and ea ...
, Zambia,
Malawi Malawi (; or aláwi Tumbuka: ''Malaŵi''), officially the Republic of Malawi, is a landlocked country in Southeastern Africa that was formerly known as Nyasaland. It is bordered by Zambia to the west, Tanzania to the north and northeas ...
,
Tanzania Tanzania (; ), officially the United Republic of Tanzania ( sw, Jamhuri ya Muungano wa Tanzania), is a country in East Africa within the African Great Lakes region. It borders Uganda to the north; Kenya to the northeast; Comoro Islands ...
, and
Kenya ) , national_anthem = " Ee Mungu Nguvu Yetu"() , image_map = , map_caption = , image_map2 = , capital = Nairobi , coordinates = , largest_city = Nairobi ...
also produce aquamarine.


Emerald

Emerald is green beryl, colored by around 2% chromium and sometimes vanadium. Most emeralds are highly included, so their brittleness (resistance to breakage) is classified as generally poor., The modern English word "emerald" comes via
Middle English Middle English (abbreviated to ME) is a form of the English language that was spoken after the Norman conquest of 1066, until the late 15th century. The English language underwent distinct variations and developments following the Old English ...
''emeraude'', imported from modern French via
Old French Old French (, , ; Modern French: ) was the language spoken in most of the northern half of France from approximately the 8th to the 14th centuries. Rather than a unified language, Old French was a linkage of Romance dialects, mutually intellig ...
''ésmeraude'' and
Medieval Latin Medieval Latin was the form of Literary Latin used in Roman Catholic Western Europe during the Middle Ages. In this region it served as the primary written language, though local languages were also written to varying degrees. Latin functione ...
, from
Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...
, from
Greek Greek may refer to: Greece Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group. *Greek language, a branch of the Indo-European language family. **Proto-Greek language, the assumed last common ancestor ...
σμάραγδος ''smaragdos'' meaning ‘green gem’, from Hebrew ברקת ''bareket'' (one of the twelve stones in the Hoshen pectoral pendant of the Kohen HaGadol), meaning ‘lightning flash’, referring to ‘emerald’, relating to Akkadian ''baraqtu'', meaning ‘emerald’, and possibly relating to the
Sanskrit Sanskrit (; attributively , ; nominally , , ) is a classical language belonging to the Indo-Aryan branch of the Indo-European languages. It arose in South Asia after its predecessor languages had diffused there from the northwest in the late ...
word मरकत ''marakata'', meaning ‘green’. The Semitic word אזמרגד ''izmargad'', meaning ‘emerald’, is a back-loan, deriving from Greek smaragdos. Emeralds in antiquity were mined by the Egyptians and in what is now
Austria Austria, , bar, Östareich officially the Republic of Austria, is a country in the southern part of Central Europe, lying in the Eastern Alps. It is a federation of nine states, one of which is the capital, Vienna, the most populous ...
, as well as Swat in contemporary
Pakistan Pakistan ( ur, ), officially the Islamic Republic of Pakistan ( ur, , label=none), is a country in South Asia. It is the world's fifth-most populous country, with a population of almost 243 million people, and has the world's second-lar ...
. A rare type of emerald known as a
trapiche emerald 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, sa ...
is occasionally found in the mines of Colombia. A trapiche emerald exhibits a "star" pattern; it has raylike spokes of dark carbon impurities that give the emerald a six-pointed radial pattern. It is named for the ''
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 t ...
'', a grinding wheel used to process sugarcane in the region.
Colombian emeralds Emeralds are green precious gemstones that are mined in various geological settings. They are minerals in the beryl group of silicates. For more than 4,000 years, emeralds have been among the most valuable of all jewels. Colombia, located in n ...
are generally the most prized due to their transparency and fire. Some of the rarest emeralds come from the two main emerald belts in the
Eastern Ranges The Eastern Ranges is an Australian rules football team in the NAB League, the Victorian statewide under-18s competition. The club is a founding member of the competition (1992) and has produced several players for the Australian Football Leag ...
of the Colombian
Andes The Andes, Andes Mountains or Andean Mountains (; ) are the longest continental mountain range in the world, forming a continuous highland along the western edge of South America. The range is long, wide (widest between 18°S – 20°S ...
: Muzo and Coscuez west of the
Altiplano Cundiboyacense The Altiplano Cundiboyacense () is a high plateau located in the Eastern Cordillera of the Colombian Andes covering parts of the departments of Cundinamarca and Boyacá. The altiplano corresponds to the ancient territory of the Muisca. The Alt ...
, and Chivor and Somondoco to the east. Fine emeralds are also found in other countries, such as
Zambia Zambia (), officially the Republic of Zambia, is a landlocked country at the crossroads of Central, Southern and East Africa, although it is typically referred to as being in Southern Africa at its most central point. Its neighbours are t ...
,
Brazil Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...
,
Zimbabwe Zimbabwe (), officially the Republic of Zimbabwe, is a landlocked country located in Southeast Africa, between the Zambezi and Limpopo Rivers, bordered by South Africa to the south, Botswana to the south-west, Zambia to the north, and ...
,
Madagascar Madagascar (; mg, Madagasikara, ), officially the Republic of Madagascar ( mg, Repoblikan'i Madagasikara, links=no, ; french: République de Madagascar), is an island country in the Indian Ocean, approximately off the coast of East Africa ...
,
Pakistan Pakistan ( ur, ), officially the Islamic Republic of Pakistan ( ur, , label=none), is a country in South Asia. It is the world's fifth-most populous country, with a population of almost 243 million people, and has the world's second-lar ...
,
India India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the so ...
,
Afghanistan Afghanistan, officially the Islamic Emirate of Afghanistan,; prs, امارت اسلامی افغانستان is a landlocked country located at the crossroads of Central Asia and South Asia. Referred to as the Heart of Asia, it is bordere ...
and
Russia Russia (, , ), or the Russian Federation, is a transcontinental country spanning Eastern Europe and Northern Asia. It is the largest country in the world, with its internationally recognised territory covering , and encompassing one-eig ...
. In the US, emeralds can be found in
Hiddenite, North Carolina Hiddenite is a census-designated place (CDP) in east-central Alexander County, North Carolina, United States. The population was 536 at the 2010 census. It is part of the Hickory–Lenoir– Morganton Metropolitan Statistical Area. Histor ...
. In 1998, emeralds were discovered in
Yukon Yukon (; ; formerly called Yukon Territory and also referred to as the Yukon) is the smallest and westernmost of Canada's three territories. It also is the second-least populated province or territory in Canada, with a population of 43,964 as ...
. Emerald is a rare and valuable gemstone and, as such, it has provided the
incentive In general, incentives are anything that persuade a person to alter their behaviour. It is emphasised that incentives matter by the basic law of economists and the laws of behaviour, which state that higher incentives amount to greater levels of ...
for developing synthetic emeralds. Both hydrothermal and ''flux-growth'' synthetics have been produced. The first commercially successful emerald synthesis process was that of Carroll Chatham. The other large producer of flux emeralds was Pierre Gilson Sr., which has been on the market since 1964. Gilson's emeralds are usually grown on natural colorless beryl seeds which become coated on both sides. Growth occurs at the rate of per month, a typical seven-month growth run producing emerald crystals of 7 mm of thickness. The green color of emeralds is widely attributed to presence of Cr3+ ions. Intensely green beryls from Brazil, Zimbabwe and elsewhere in which the color is attributed to vanadium have also been sold and certified as emeralds.


Golden beryl and heliodor

''Golden beryl'' can range in colors from pale yellow to a brilliant gold. Unlike emerald, golden beryl generally has very few flaws. The term "golden beryl" is sometimes synonymous with ''heliodor'' (from Greek ''hēlios – ἥλιος'' "sun" + ''dōron – δῶρον'' "gift") but golden beryl refers to pure yellow or golden yellow shades, while heliodor refers to the greenish-yellow shades. The golden yellow color is attributed to Fe3+ ions. Both golden beryl and heliodor are used as gems. Probably the largest cut golden beryl is the flawless 2054- carat stone on display in the Hall of Gems,
Washington, D.C. ) , image_skyline = , image_caption = Clockwise from top left: the Washington Monument and Lincoln Memorial on the National Mall, United States Capitol, Logan Circle, Jefferson Memorial, White House, Adams Morgan, ...
, United States.


Goshenite

Colorless beryl is called ''goshenite''. The name originates from
Goshen, Massachusetts Goshen is a town in Hampshire County, Massachusetts, United States. The population was 960 at the 2020 census. It is part of the Springfield, Massachusetts Metropolitan Statistical Area. The town has a rural atmosphere, with one general store, ...
, where it was originally discovered. In the past, goshenite was used for manufacturing eyeglasses and lenses owing to its transparency. Nowadays, it is most commonly used for gemstone purposes. The gem value of goshenite is relatively low. However, goshenite can be colored yellow, green, pink, blue and in intermediate colors by irradiating it with high-energy particles. The resulting color depends on the content of Ca, Sc, Ti, V, Fe, and Co impurities.


Morganite

Morganite, also known as "pink beryl", "rose beryl", "pink emerald" (which is not a legal term according to the new Federal Trade Commission Guidelines and Regulations), and "cesian (or ''caesian'') beryl", is a rare light pink to rose-colored gem-quality variety of beryl. Orange/yellow varieties of morganite can also be found, and color banding is common. It can be routinely heat treated to remove patches of yellow and is occasionally treated by irradiation to improve its color. The pink color of morganite is attributed to Mn2+ ions.


Red beryl

Red variety of beryl (the "bixbite") was first described in 1904 for an occurrence, its type locality, at Maynard's Claim (Pismire Knolls), Thomas Range,
Juab County Juab County ( ) is a county in western Utah, United States. As of the 2010 United States Census, the population was 10,246. Its county seat and largest city is Nephi. Juab County is part of the Provo–Orem, Utah Metropolitan Statistical ...
,
Utah Utah ( , ) is a state in the Mountain West subregion of the Western United States. Utah is a landlocked U.S. state bordered to its east by Colorado, to its northeast by Wyoming, to its north by Idaho, to its south by Arizona, and to it ...
. The dark red color is attributed to Mn3+ ions. Old synonym "bixbite" is deprecated from the CIBJO because of the possibility of confusion with the mineral
bixbyite Bixbyite is a manganese iron oxide mineral with chemical formula: (Mn,Fe)2O3. The iron/manganese ratio is quite variable and many specimens have almost no iron. It is a metallic dark black with a Mohs hardness of 6.0 - 6.5. It is a somewhat rare ...
(both named after mineralogist
Maynard Bixby Maynard Bixby (June 28, 1853 – February 18, 1935) was an American mineralogist and mineral collector. Early life Bixby was born in Wyalusing, Pennsylvania and graduated from Lafayette College in Easton, Pennsylvania in 1876. He worked for a tim ...
). Red "bixbite" beryl formerly was marketed as "red" or "scarlet emerald", but these terms involving "Emerald" terminology are now prohibited in the US. Red beryl is very rare and has only been reported from a handful of North American locations: Wah Wah Mountains,
Beaver County, Utah Beaver County is a county in west central Utah, United States. As of the 2010 United States Census, the population was 6,629. Its county seat and largest city is Beaver. The county was named for the abundance of beaver in the area. History Expl ...
; Paramount Canyon, Round Mountain, Juab County, Utah; and
Sierra County, New Mexico Sierra County is a county located in the U.S. state of New Mexico. As of the 2020 Census, the population was 11,576. Its county seat is Truth or Consequences. Geography According to the U.S. Census Bureau, the county has a total area of , of ...
, although this locality does not often produce gem-grade stones. The bulk of gem-grade red beryl comes from the Ruby-Violet Claim in the Wah Wah Mts. of midwestern Utah, discovered in 1958 by Lamar Hodges, of
Fillmore, Utah Fillmore is a city and the county seat of Millard County, Utah, United States. The population was 2,435 at the 2010 United States Census. It is named for the thirteenth US President Millard Fillmore, who was in office when Millard County was cre ...
, while he was prospecting for
uranium Uranium is a chemical element with the symbol U and atomic number 92. It is a silvery-grey metal in the actinide series of the periodic table. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons. Uranium is weak ...
. Red beryl has been known to be confused with pezzottaite, a caesium analog of beryl, found in Madagascar and, more recently, Afghanistan; cut gems of the two varieties can be distinguished by their difference in
refractive index In optics, the refractive index (or refraction index) of an optical medium is a dimensionless number that gives the indication of the light bending ability of that medium. The refractive index determines how much the path of light is bent, or ...
, and the rough crystals easily by their differing crystal systems (pezzottaite trigonal, red beryl hexagonal). Synthetic red beryl is also produced. Like emerald and unlike most other varieties of beryl, the red ones are usually highly included. While gem beryls are ordinarily found in pegmatites and certain metamorphic stones, red beryl occurs in topaz-bearing rhyolites. It is formed by crystallizing under low pressure and high temperature from a pneumatolytic phase along fractures or within near-surface miarolitic cavities of the rhyolite. Associated minerals include bixbyite,
quartz Quartz is a hard, crystalline mineral composed of silica ( silicon dioxide). The atoms are linked in a continuous framework of SiO4 silicon-oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical ...
,
orthoclase Orthoclase, or orthoclase feldspar ( endmember formula K Al Si3 O8), is an important tectosilicate mineral which forms igneous rock. The name is from the Ancient Greek for "straight fracture," because its two cleavage planes are at right angles ...
, topaz, spessartine, pseudobrookite and hematite.


See also

* * * List of emeralds by size


References


Further reading

*


External links

* * {{Authority control * Hexagonal minerals Minerals in space group 192