Emerald

Green gemstone, a beryl variety


title: "Emerald" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["beryl-group"] description: "Green gemstone, a beryl variety" topic_path: "general/beryl-group" source: "https://en.wikipedia.org/wiki/Emerald" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0

::summary Green gemstone, a beryl variety ::

::data[format=table title="Infobox mineral"]

FieldValue
nameEmerald
categoryBeryl variety
boxbgcolor#50C878
boxtextcolorblack
imageBéryl var. émeraude sur gangue (Muzo Mine Boyaca - Colombie) 2.jpg
imagesize260
captionEmerald crystal from Muzo, Colombia
symmetry(6/m 2/m 2/m) – dihexagonal dipyramidal
unit cella = 9.21 Å, c = 9.19 Å; Z = 2
formulaBe3Al2(SiO3)6
molweight537.50
colorBluish green to green
habitMassive to well Crystalline
systemHexagonal (6/m 2/m 2/m) Space group: P6/mсc
cleavageImperfect on the [0001]
fractureConchoidal
mohs7.5–8
lusterVitreous
opticalpropUniaxial (−)
refractivenω = 1.564–1.595,
nε = 1.568–1.602
birefringenceδ = 0.0040–0.0070
fluorescenceNone (some fracture-filling materials used to improve emerald's clarity do fluoresce, but the stone itself does not)
streakWhite
gravityAverage 2.76
diaphaneityTransparent to opaque
references
::

| name = Emerald | category = Beryl variety | boxwidth = | boxbgcolor = #50C878 | boxtextcolor = black | image = Béryl var. émeraude sur gangue (Muzo Mine Boyaca - Colombie) 2.jpg | imagesize = 260 | caption = Emerald crystal from Muzo, Colombia | symmetry = (6/m 2/m 2/m) – dihexagonal dipyramidal | unit cell = a = 9.21 Å, c = 9.19 Å; Z = 2 | formula = Be3Al2(SiO3)6 | molweight = 537.50 | color = Bluish green to green | habit = Massive to well Crystalline | system = Hexagonal (6/m 2/m 2/m) Space group: P6/mсc | twinning = | cleavage = Imperfect on the [0001] | fracture = Conchoidal | tenacity = | mohs = 7.5–8 | luster = Vitreous | polish = | opticalprop = Uniaxial (−) | refractive = nω = 1.564–1.595, nε = 1.568–1.602 | birefringence = δ = 0.0040–0.0070 | dispersion = | pleochroism = | fluorescence= None (some fracture-filling materials used to improve emerald's clarity do fluoresce, but the stone itself does not) | absorption = | streak = White | gravity = Average 2.76 | density = | melt = | fusibility = | diagnostic = | solubility = | diaphaneity = Transparent to opaque | other = | references = ::figure[src="https://upload.wikimedia.org/wikipedia/commons/f/f3/Emeraude_gisements.jpg" caption="Main emerald producing countries"] ::

Emerald is a gemstone and a variety of the mineral beryl (Be3Al2(SiO3)6) colored green by trace amounts of chromium or sometimes vanadium. Beryl has a hardness of 7.5–8 on the Mohs scale. so their toughness (resistance to breakage) is classified as generally poor. Emerald is a cyclosilicate. It occurs mainly in association with quartz, muscovite, albite, schorl, microcline, fluorite, smoky quartz and elbaite.

Etymology

The word "emerald" is derived (via and ), from Vulgar Latin: esmaralda/esmaraldus, a variant of Latin smaragdus, which was via (smáragdos; "green gem"). The Greek word may have a Semitic, Sanskrit or Persian origin. According to Webster's Dictionary the term emerald was first used in the 14th century.

Properties determining value

::figure[src="https://upload.wikimedia.org/wikipedia/commons/1/1a/5_Emeralds_from_Colombia.JPG" caption="Cut emeralds"] ::

Emeralds, like all colored gemstones, are graded using four basic parameters known as "the four Cs": color, clarity, cut and carat weight. Normally, in grading colored gemstones, color is by far the most important criterion. A fine emerald must possess not only 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" precious gems along with diamonds, rubies and sapphires.

Chromium, vanadium, and iron are the trace elements that cause emerald’s color. The presence or absence of each and their relative amounts determine the exact color of an emerald crystal.

Color

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 Dark green. Yellow and blue are 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 well-saturated and have a hue that is bright (vivid). Gray is the normal saturation modifier or mask found in emeralds; a grayish-green hue is a dull-green hue.

Clarity

::figure[src="https://upload.wikimedia.org/wikipedia/commons/1/1e/Emerald_in_a_quartz_and_pegmatite_matrix.JPG" caption="0756633427}}."] ::

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 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 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.

Treatments

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 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 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. 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 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.

Emerald mines

::figure[src="https://upload.wikimedia.org/wikipedia/commons/b/b5/Trapiche_emerald_(cropped).jpg" caption="A Colombian [[trapiche emerald"] ::

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 the discovery of the Colombian deposits. Today, only ruins remain in Egypt.

Colombia is historically the world's largest producer of emeralds, with the quantity varying 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 is the world's second biggest producer, with its Kafubu River area deposits (Kagem Mines) about 45 km 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, the United States, Zambia, and Zimbabwe. In the US, emeralds have been found in Connecticut, Montana, Nevada, North Carolina, and South Carolina.

Origin determinations

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 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 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.

Synthetic emerald

::figure[src="https://upload.wikimedia.org/wikipedia/commons/6/6a/Emerald.png" caption="Emerald showing its hexagonal structure"] ::

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 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 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 "Esmeralda", and they were grown as 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 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 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. ::figure[src="https://upload.wikimedia.org/wikipedia/commons/1/11/SyntEmerald_0302.jpg" caption="Emerald made by hydrothermal synthesis"] ::

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 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."

Historical and cultural references

The virtue of the Emerald is to counteract poison. They say that if 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.{{cite book |last1 = Ruland |first1 = Martin |author-link1 = Martin Ruland the Younger |translator-last1 = Waite |translator-first1 = Arthur Edward |translator-link1 = Arthur Edward Waite |orig-date = 1612 |chapter = Smaragdus |trans-title = Lexicon alchemia |title = A Lexicon of Alchemy |date = May 26, 2014 |url = https://books.google.com/books?id=vWmjAwAAQBAJ |location = Altenmünster, Bavaria |publisher = Jazzybee Verlag |publication-date = 2014 |page = |isbn = 978-3-8496-4439-0 |access-date = 25 June 2022 |quote = The virtue of the Emerald is to counteract poison. They say that if 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, it worn at the time on the finger. |archive-date = June 25, 2022 |archive-url = https://web.archive.org/web/20220625041552/https://books.google.com/books?id=vWmjAwAAQBAJ |url-status = live }} ::

  • According to French writer Brantôme ( 1540–1614) Hernán Cortés had one of the emeralds which he had looted from Mexico text engraved, Inter Natos Mulierum non surrexit major ("Among those born of woman there hath not arisen a greater," Matthew 11:11), in reference to John the Baptist. Brantôme considered engraving such a beautiful and simple product of nature sacrilegious and considered this act the cause for Cortez's loss in 1541 of an extremely precious pearl,To which he dedicated the work, A beautiful and incomparable pearl and even for the death of King Charles IX of France, who died (1574) soon afterward.Compare: |last1 = de Bourdeill |first1 = Pierre |author-link1 = Pierre de Bourdeille, seigneur de Brantôme |editor-last1 = Lalanne |editor-first1 = Ludovic |editor-link1 = Ludovic Lalanne |volume = 1: Grand Capitaines Estrangers |title = Oeuvres complètes de Pierre de Bourdeille, seigneur de Brantome publièes d'après les manuscrits avec variantes et fragments inédits pour la Société de l'histoire de France |year = 1864 |url = https://books.google.com/books?id=hh3RcvRZbLoC |language = fr |location = Paris |publisher = Jules Renouard |publication-date = 1864 |page = 52 |access-date = 25 June 2022 |quote = [...] la belle et incomparable perle de cet Hernand Cortez, qu'il rapporta des Indes, sur laquelle il fit graver ces mots: Inter natos mulierum non surrexit major, [...] laquelle il perdit depuis devant Alger [...]. [...] Brantôme s'est trompé ici: le joyau dont il parle n'était point une perle, mais une émaraude. |archive-date = 25 June 2022 |archive-url = https://web.archive.org/web/20220625041412/https://books.google.com/books?id=hh3RcvRZbLoC |url-status = live
  • In American author L. Frank Baum's 1900 children's novel The Wonderful Wizard of Oz, and the 1939 MGM film adaptation, the protagonist must travel to an Emerald City to meet the eponymous character, the Wizard.
  • The chief deity of one of India's most famous temples, the Meenakshi Amman Temple in Madurai, is the goddess Meenakshi, whose idol is traditionally thought to be made of emerald.

Notable emeralds

::data[format=table]

EmeraldOriginSizeLocation
ChipembeleZambia, 20217,525 carats (1.505 kg)Israel Diamond Exchange, Eshed – Gemstar
url=https://www.telegraph.co.uk/news/worldnews/northamerica/usa/8023359/Judge-to-decide-who-owns-250-million-Bahia-emerald.htmltitle=Judge to decide who owns 250 million Bahia emerald.htmlwork=The Daily Telegraph, UKdate=24 September 2010
Carolina EmperorUnited States, 2009310 carats uncut, 64.8 carats cutNorth Carolina Museum of Natural Sciences, Raleigh
Chalk EmeraldColombia38.40 carats cut, then recut to 37.82 caratsNational Museum of Natural History, Washington
Duke of Devonshire EmeraldColombia, before 18311,383.93 carats uncutNatural History Museum, London
Emerald of Saint LouisAustria, probably Habachtal51.60 carats cutNational Museum of Natural History, Paris
Gachalá EmeraldColombia, 1967858 carats uncutNational Museum of Natural History, Washington
Mogul Mughal EmeraldColombia, 1107 A.H. (1695–1696 AD)217.80 carats cutMuseum of Islamic Art, Doha, Qatar
Rockefeller EmeraldColombia18.04 carats Octagonal step-cutPrivate collection
Patricia EmeraldColombia, 1920632 carats uncut, dihexagonal (12 sided)American Museum of Natural History, New York
Mim EmeraldColombia, 20141,390 carats uncut, dihexagonal (12 sided)Mim Museum, Beirut
::

Gallery

File:Patricia Emerald 1.jpg | emeralds File:Émeraude, quartz 2.jpg|Emerald on quartz, from Carnaiba Mine, Pindobaçu, Campo Formoso ultramafic complex, Bahia, Brazil File:Chalk emerald 03.jpg|The Chalk Emerald ring, containing a top-quality 37-carat emerald, in the U.S. National Museum of Natural History File:Зүмірет.jpg|Emerald crystals File:Beryl-130023.jpg|A 5-carat emerald from Muzo with hexagonal cross-section File:Gachala Emerald 3526711557 849c4c7367.jpg|Gachalá Emerald, one of the largest gem emeralds in the world, at 858 carat. Found in 1967 at La Vega de San Juan mine in Gachalá, Colombia. Housed at the National Museum of Natural History in Washington, D.C. File:Béryl var. émeraude sur gangue (Muzo Mine Boyaca - Colombie) -2.jpg|Colombian emeralds File:Rough emerald crystals from Panjshir Valley Afghanistan.jpg|Rough emerald crystals from Panjshir Valley Afghanistan File:Mim emerald.jpg|Large, di-hexagonal prismatic crystal of 1,390 carats uncut with a deep green color. It is transparent and features few inclusions in the upper 2/3, and is translucent in the lower part. Housed at the Mim Museum, Beirut, Lebanon. File:Emeralds & Aquamarines.jpg | Cut Emeralds File:Sand and emerald from Habachtal, Salzburg, Austria.jpg | Habachtal emerald

Notes

References

References

  1. Hurlbut, Cornelius S. Jr., and Kammerling, Robert C. (1991). ''Gemology'', John Wiley & Sons, New York, p. 203, {{ISBN. 0-471-52667-3.
  2. "Emerald Quality Factors". Gemological Institute of America.
  3. "Definition of 'emerald'".
  4. "smaragdus NOUN".
  5. {{OEtymD. emerald
  6. "Definition of EMERALD".
  7. Wise, R. W. (2001) ''Secrets of the Gem Trade: the connoisseur's guide to precious gemstones''. Brunswick House Press, p. 108, {{ISBN. 0-9728223-8-0.
  8. "Emerald Value, Price, and Jewelry Information".
  9. Gemological Institute of America. "Emerald Quality Factors".
  10. [http://gia4cs.gia.edu/EN-US/gr-colored-diamonds-gemstones.htm Grading Fancy-Color Diamonds] {{webarchive. link. (2 November 2014 . Gemological Institute of America)
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  12. [http://www.gia.edu/emerald-quality-factor Emerald Quality Factors] {{webarchive. link. (23 February 2014 . Gemological Institute of America.)
  13. (1991). "Gems & Gemology". Gems & Gemology.
  14. (2001). "Emerald Treatments". Kiefert.
  15. Liccini, Mark. [http://www.gemsociety.org/article/emerald-enhancement/ Understanding Emerald Enhancements and Treatments] {{webarchive. link. (21 December 2014 . International Gem Society)
  16. (22 October 2013). "Gemmology". Elsevier.
  17. (2009). "Jewelry & Gems, the Buying Guide: How to Buy Diamonds, Pearls, Colored Gemstones, Gold & Jewelry with Confidence and Knowledge". Gemstone Press.
  18. (2000). "Oxygen Isotopes and Emerald Trade Routes Since Antiquity". Science.
  19. "Romans organized the mines as a multinational business..." Finlay, Victoria. Jewels: A Secret History (Kindle Location 3098). Random House Publishing Group. Kindle Edition.
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  21. Dydyński, Krzysztof. (2003). "Colombia". Lonely Planet.
  22. Branquet, Y. Laumenier, B. Cheilletz, A. & Giuliani, G.. (1999). "Emeralds in the Eastern Cordillera of Colombia. Two tectonic settings for one mineralization". Geology.
  23. Carrillo, V. (2001). Compilación y análisis de la información geológica referente a la explotación esmeraldífera en Colombia. Informe de contrato 124. INGEOMINAS
  24. Wacaster, Susan. (March 2012). "2010 Minerals Yearbook: Colombia [ADVANCE RELEASE]". [[United States Geological Survey]].
  25. [http://www.emeralds.com/specimens/specimens/mining.html Emerald Mining Areas in Colombia] {{webarchive. link. (29 September 2010 , with location map of these three districts.)
  26. Behling, Steve and Wilson, Wendell E. (1 January 2010) "[http://www.highbeam.com/doc/1G1-219077097.html The Kagem emerald mine: Kafubu Area, Zambia]", ''The Mineralogical Record'' {{webarchive. link. (10 May 2013)
  27. (November 2025). "What is Kagem Zambian Emerald?".
  28. "[http://economia.uol.com.br/ultimas-noticias/redacao/2012/01/18/maior-esmeralda-do-mundo-encontrada-no-brasil-sera-leiloada-no-canada.jhtm Maior esmeralda do mundo, encontrada no Brasil, será leiloada no Canadá] {{webarchive. link. (April 7, 2014 ". UOL (18 January 2012))
  29. (19 July 2010). "Emerald at Mindat". Mindat.org.
  30. In 1998, emeralds were discovered in the Yukon Territory of Canada.[http://www.geology.gov.yk.ca/pdf/emeralds.pdf Emeralds in the Yukon Territory] {{webarchive. link. (31 March 2014 . Yukon Geological Survey.)
  31. (2012). "Determining the geographical origins of natural emeralds through nondestructive chemical fingerprinting". Journal of Gemmology.
  32. (1988). "Gemstones". Springer Netherlands.
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  34. Geological Magazine "Hydrothermal process for growing crystals having the structure of beryl in an alkaline halide medium" {{US patent. 3567642 Issue date: 2 March 1971
  35. (2006–2007). "A new type of Tairus hydrothermally-grown synthetic emerald, colored by vanadium and copper". Journal of Gemmology of Gemmological Association of Great Britain.
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  40. "Meenakshi Temple – Meenakshi Temple of Madurai, Meenakshi Amman Temple Madurai India".
  41. (8 November 2021). "Gemfields finds largest emerald ever at Zambia mine".
  42. (2 November 2022). "World's largest uncut emerald weighs hefty 1.5 kg". Guinness World Records Limited.
  43. Allen, Nick. (24 September 2010). "Judge to decide who owns 250 million Bahia emerald.html". [[The Daily Telegraph]], UK.
  44. "The Curse of the Bahia Emerald, a Giant Green Rock That Ruins Lives". wired.com.
  45. Gast, Phil. (1 September 2010). "North Carolina emerald: Big, green and very rare". Cable News Network (Turner Broadcasting System, Inc.).
  46. Stancill, Jane. (16 March 2012). "N.C. gems to shine at museum". The News & Observer Publishing Co..
  47. "Emeraude de Saint Louis – St Louis Emerald". CRPG: Le Centre de Recherches Pétrographiques et Géochimiques.
  48. (2017). "Gachala Emerald". Smithsonian Institution.
  49. "10 jewels that made history".
  50. "Patricia Emerald".
  51. Bouillard, J.-C. and Jeanne-Michaud, A. (2016) "101 minéraux et pierres précieuses – qu'il faut avoir vus dans sa vie". Hors collection, Dunod. {{ISBN. 2100742272.

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beryl-group