Difference between revisions of "Emerald" - New World Encyclopedia

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{{Infobox mineral
 
{{Infobox mineral
| name       = Emerald
+
| name = Emerald
| category   =  
+
| category =  
| boxwidth   =  
+
| boxwidth =  
| boxbgcolor = green
+
| boxbgcolor = green
| image       = Emerald specimen with matrix.jpg
+
| image = Emerald specimen with matrix.jpg
| imagesize   = 150
+
| imagesize = 150
| caption     = Emerald with host rock
+
| caption = Emerald with host rock
| formula     = [[Beryllium]] [[aluminium]] [[silicate]] with [[chromium]], <!--
+
| formula = [[Beryllium]] [[aluminum]] [[silicate]] with [[chromium]], <!--
                —>Be<sub>3</sub>Al<sub>2</sub>(SiO<sub>3</sub>)<sub>6</sub>::Cr
+
—>Be<sub>3</sub>Al<sub>2</sub>(SiO<sub>3</sub>)<sub>6</sub>::Cr
| molweight   =  
+
| molweight =  
| color       = Green
+
| color = Green
| habit       = Hexagonal Crystals
+
| habit = Hexagonal Crystals
| system     = Hexagonal
+
| system = Hexagonal
| twinning   =  
+
| twinning =  
| cleavage   = Poor Basal Cleavage (Seldom Visible)
+
| cleavage = Poor Basal Cleavage (Seldom Visible)
| fracture   = Conchoidal
+
| fracture = Conchoidal
| mohs       = 7.5 - 8.0
+
| mohs = 7.5 - 8.0
| luster     = Vitreous
+
| luster = Vitreous
| refractive = 1.576 - 1.582
+
| refractive = 1.576 - 1.582
 
| opticalprop =  
 
| opticalprop =  
 
| birefringence =  
 
| birefringence =  
 
| pleochroism = Distinct, Blue-Green/Yellow-Green
 
| pleochroism = Distinct, Blue-Green/Yellow-Green
| streak     = White
+
| streak = White
| gravity     = 2.70 - 2.78
+
| gravity = 2.70 - 2.78
| density     =  
+
| density =  
| melt       =  
+
| melt =  
| fusibility =  
+
| fusibility =  
| diagnostic =  
+
| diagnostic =  
| solubility =  
+
| solubility =  
 
| diaphaneity =  
 
| diaphaneity =  
| other       =  
+
| other =  
 
}}
 
}}
  
'''Emerald''' (Be<sub>3</sub>Al<sub>2</sub>(SiO<sub>3</sub>)<sub>6</sub>) is a variety of the [[mineral]] [[beryl]], colored green by trace amounts of [[chromium]] and sometimes [[iron]].  It is highly prized as a [[gemstone]] and by weight is the most valuable gemstone in the world, although it is often made less so by [[inclusion (mineral)|inclusions]], which all emeralds have to some degree. Beryl has a [[hardness]] of 7.5 on the 10 point [[Mohs scale of mineral hardness|Mohs scale]] of hardness. However, this Mohs rating can decrease, depending on the number and severity of inclusions in a particular stone.
+
'''Emerald''' (from the [[Greek]] word ''smaragdos'', through the [[French]] ''esmeralde'', meaning "green gemstone") is a green variety of the [[mineral]] [[beryl]] and is among the most valuable [[gemstone]]s in the world. Harder than [[quartz]] but softer than [[diamond]], the emerald usually contains many [[inclusions]] trapped during its formation. In mineralogy, an "inclusion" is any material trapped within a mineral during its formation. Synthetic emeralds that appear similar to the natural crystals are also being produced.
 +
{{toc}}
 +
Although the possession of emeralds is indicative of wealth and luxury, we need to bear in mind that these (and other) gemstones were recovered by the hard labor of miners working under difficult circumstances, often placing their lives in danger.
 +
 
 +
== Formation and occurrence ==
 +
 
 +
[[Image:Gachala Emerald.jpg|thumb|250px|left|The Gachala Emerald, at 858 carats, is one of the largest gem emeralds in the world. It was found in 1967 at the La Vega de San Juan mine in Gachalá, Colombia.]]
 +
 
 +
It is thought that the elemental constituents of emerald were brought together during such geological processes as orogenesis (mountain building), metamorphism (a solid-state recrystallization of the rock) based on changes in heat, pressure, and the introduction of fluids, and land erosion. Later, crystals of the gemstones were formed. Each natural crystal retains a number of "flaws"—such as crystalline inclusions, bubbles, and fissures—that are a result of the geological processes by which it was formed.
  
Most emeralds are oiled as part of the post [[lapidary]] process. The amount of oil entering an emerald microfissure is roughly equivalent to the size of a period in print.
+
Emeralds in antiquity were mined by the people of [[Egypt]], [[Austria]], and northern [[Pakistan]].<ref>Giuliani, Gaston, et.al. “Oxygen Isotopes and Emerald Trade Routes Since Antiquity.” ''Science,'' January 28, 2000, pp. 631-633.</ref> Today, [[Colombia]] leads the world in terms of the number and size of emerald deposits found. In addition, quality emeralds are found in [[Brazil]], [[Zambia]], [[Zimbabwe]], [[Madagascar]], Pakistan, [[Afghanistan]], [[India]], and [[Russia]].
  
Emeralds come in many shades of green and bluish green. There is a wide spectrum of clarity, along with various numbers of inclusions. Most emeralds are highly included, so it is quite rare to find an emerald with only minor inclusions. Because of the usual inclusions, the toughness (resistance to breakage) is classified as generally poor.
+
A rare type of stone known as a "trapiche emerald" is occasionally found in the mines of [[Colombia]]. A trapiche emerald contains rays of dark carbon impurities that produce a six-pointed starlike pattern. It is named for the ''trapiche,'' a grinding wheel used to process [[sugarcane]] in the region.<ref>Davidson, Michael W. [http://micro.magnet.fsu.edu/birthstones/pages/emerald.html Emerald] Retrieved May 17, 2007.</ref>
  
Emeralds in antiquity were mined by the [[Egyptians]] and in [[Austria]] as well as [[Swat]] in northern [[Pakistan]].<ref>Giuliani et al (2000): “Oxygen Isotopes and Emerald Trade Routes Since Antiquity.” Gaston Giuliani, Marc Chaudisson, Henri-Jean Schubnel, Daniel-H. Piat, Claire Rollion-Bard, Christian France-Lanord, Didier Giard, Daniel de Narvaez, Benjamin Rondeau. ''Science'', January 28, 2000, pp. 631-633.</ref> <ref>Giuliani et al (2000b): “La route des emeraudes anciennes.” Gaston Giuliani, Michèle Heuze, Marc Chaudisson. ''Pour la Science'', Nov. 2000, pp. 58-65.</ref>
+
== Characteristics ==
  
A rare type of emerald known as a trapiche emerald 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 grinding wheel used to process [[sugarcane]] in the region. [http://micro.magnet.fsu.edu/birthstones/pages/emerald.html]
+
The mineral beryl consists of beryllium aluminum silicate (Be<sub>3</sub>Al<sub>2</sub>(SiO<sub>3</sub>)<sub>6</sub>), and the emerald variety is colored green by the presence of traces of [[chromium]] or [[vanadium]], and sometimes [[iron]]. The color varies in shades of green and bluish green. In addition, emeralds come in a wide spectrum of clarity, along with various numbers of inclusions.
  
==Synthetic emerald==
+
The emerald has a hexagonal [[crystal]] structure and a [[hardness]] of about 7.5 on the 10-point [[Mohs scale of mineral hardness|Mohs scale]] of hardness. This hardness rating decreases, however, with an increase in the number of inclusions in the stone. Most emeralds have many inclusions, and it is rare to find an emerald with only minor inclusions. Consequently, the toughness (resistance to breakage) is generally rated as poor.
[[Image:Emerald.png|thumb|100px|left|Emerald showing its hexagonal structure]]
 
Emerald is a rare and valuable gemstone and, as such, it has provided the incentive for developing synthetic emeralds. 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 C. Chatham. Because Chatham's emeralds do not have any water and contain traces of vanadate, molybdenum and vanadium, a lithium vanadate flux process is probably involved. The other large producer of flux emeralds is 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 1 mm per month and a typical seven-month growth run produces emeralds crystals of 7 mm of thickness (Nassau, K. Gems Made By Man, 1980).  
 
  
[[hydrothermal synthesis|Hydrothermal]] synthetic emeralds have been attributed to IG-Farben, Nacken, Chatham and others but the first satisfactory commercial product was that of Johann Lechleitner of Inbruck, Austria, which appeared on the market on the 1960's. These stones were initially sold under the names "Emerita" and "Symeralds" and they were grown as a thin layer of emerald on top of natural colorless beryl stones. Although not much is known about the original process, it is assumed that Leichleitner emeralds were grown on acid conditions. Later, from 1965 to 1970, the [[The Linde Group|Linde]] Division of [[Union Carbide]] produced completely synthetic emeralds by hydrothermal synthesis.  According to their patents (US3,567,642 and US3,567,643) 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 in order to prevent nucleation and confine growth to the seed crystals. Growth occurs by a diffusion-reaction process, assisted by convection. Typical growth conditions include pressures of 700-1400 bars at temperatures of 500 to 600 °C with a temperature gradient of 10 to 25 °C. Growth rates as fast as 1/3 mm per day can be attained.  
+
Most emeralds are oiled as part of the post-[[lapidary]] process. The amount of oil entering an emerald microfissure is roughly equivalent to the size of a period in print.
  
Flux-grown synthetic emeralds [[Fluorescence|fluoresce]] a dull red with [[long wave]] [[ultraviolet]] light, due to an indicator added during the process of synthesizing the emerald, whereas natural specimens do not.
+
==Synthetic emeralds==
 +
[[Image:Emerald.png|thumb|100px|left|Emerald showing its hexagonal structure.]]
  
Synthetic emeralds are often referred to as "created", as their chemical and gemological composition is exactly same as its natural counterparts. The [[Federal Trade Commission]] (FTC) has very strict regulations as to what can and what can not be called "synthetic" stone. The FTC says: "...[created stone must have] essentially the same optical, physical, and chemical properties as the stone named."[http://www.tairus.com/index_files/FTC_Guide.htm]
+
The rarity and value of emerald has provided the incentive for developing synthetic emeralds. Synthetics have been produced by "flux-growth" and "hydrothermal" processes, including a method for producing an emerald overgrowth on colorless beryl.
Furthermore, all natural emeralds, with the exception of the red [[Bixbite]] beryls from Utah which are [[anhydrous]], have water inclusions, as emerald is of hydrothermal origin. Flux synthetic emeralds have no water, an integral part of any natural beryl (this also accounts for flux-grown emeralds being more stable when subjected to high temperatures). Hydrothermally-grown emeralds, however, contain water molecules.
 
  
Wispy veil-like inclusions are common in flux-grown synthetic emeralds.
+
The first commercially successful process for synthetic emeralds was that of Carroll C. Chatham. Stones produced by this process do not contain water but have traces of molybdenum and vanadium, indicating that a lithium vanadate flux process was probably used. Pierre Gilson Sr. has been the other large producer of flux emeralds, which 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 millimeter (mm) per month, and a typical seven-month growth run produces emerald crystals with a thickness of 7 mm (Nassau, 1980).
 +
 
 +
[[Hydrothermal synthesis|Hydrothermal]] synthetic emeralds have been attributed to IG-Farben, Nacken, Chatham, and others, but the first satisfactory commercial product was that of Johann Lechleitner of Inbruck, Austria. These stones, which appeared on the market in the 1960s, were initially sold under the names "Emerita" and "Symeralds" and were grown as a thin layer of emerald on top of natural, colorless beryl stones. Although not much is known about the original process, it is assumed that Lechleitner emeralds were grown in acidic conditions. Later, from 1965 to 1970, the [[The Linde Group|Linde]] Division of [[Union Carbide]] produced completely synthetic emeralds by hydrothermal synthesis. According to their patents (US3,567,642 and US3,567,643), acidic conditions are essential to prevent chromium (the colorant) from precipitating. Typical growth conditions include pressures of 700-1400 bars at temperatures of 500 to 600 °C, with a temperature gradient of 10 to 25 °C. Growth rates as fast as 1/3 mm per day can be attained.
 +
 
 +
Flux-grown synthetic emeralds [[Fluorescence|fluoresce]] a dull red when examined with [[long-wave]] [[ultraviolet]] light because of an indicator added during the process of synthesis. Natural specimens, by contrast, do not fluoresce in this manner.
 +
 
 +
A synthetic emerald may be referred to as "created." Its chemical and gemological composition is exactly equivalent to that of its natural counterpart. The [[Federal Trade Commission]] (FTC) has strict regulations about what can and cannot be called "synthetic" stone. The FTC states: " [created stone must have] essentially the same optical, physical, and chemical properties as the stone named."<ref>The Federal Trade Commission, [http://www.tairus.com/index_files/FTC_Guide.htm Guide for the Jewelry Industry] Retrieved May 17, 2007.</ref>
 +
 
 +
Furthermore, all natural emeralds (except for the red [[bixbite]] beryls of Utah, which are [[anhydrous]]) have water inclusions, as they are of hydrothermal origin. Likewise, hydrothermally grown synthetic emeralds contain water molecules. On the other hand, flux-grown synthetic emeralds contain no water. For this reason, flux-grown emeralds are more stable when subjected to high temperatures. In addition, wispy, veil-like inclusions are common in flux-grown synthetic emeralds.
  
 
== Historical usage and trivia ==
 
== Historical usage and trivia ==
[[Image:Gachala Emerald.jpg|thumb|250px|right|The Gachala Emerald is one of the largest gem emeralds in the world at 858 carats. This stone was found in 1967 at La Vega de San Juan mine in Gachalá, Colombia.]]
 
  
* Emerald is regarded as the traditional [[Birthstone#Birthstones|birthstone]] for April and May , as well as the traditional gemstone for the astrological sign of [[Taurus]].  
+
* Emeralds have been highly valued since ancient times. For instance, the Aztecs and Incas of South America considered these gems holy. In addition, the Hindu scriptures known as the Vedas assert that emeralds promise good luck and enhance well-being.<ref> International Colored Gemstone Association, [http://www.gemstone.org/gem-by-gem/english/emerald.html Emerald] Retrieved May 17, 2007. </ref>
  
* According to [[Bahya ben Asher|Rebbenu Bachya]], the [[Hebrew language|Hebrew]] word "Nofech" in [[Exodus]] 28:18 means "Emerald", and was the stone on the [[Ephod]]* representing the [[tribe of Judah]]*. According to other commentaries, "Nofech" means "[[garnet]]", and another stone, the "Bareqet", representing the [[tribe of Levi]], is thought to be emerald.
+
* The green of the emerald has been taken as symbolic of spring and life itself. It is also a holy color for the [[Islam]]ic faith.
  
* In some cultures, the emerald is the traditional gift for the 55th [[wedding anniversary]]*. It is also used as a 20th and 35th wedding anniversary stone.
+
* Emerald is regarded as the [[Birthstone#Birthstones|birthstone]] for April and May, as well as the traditional gemstone for the astrological sign of [[Taurus]].
 +
 
 +
* In some cultures, the emerald is the traditional gift for the 55th [[wedding anniversary]]. It is also used as a 20th and 35th wedding anniversary stone.
 +
 
 +
* According to [[Bahya ben Asher|Rebbenu Bachya]], the [[Hebrew language|Hebrew]] word "Nofech" in [[Exodus]] 28:18 means "Emerald," and was the stone on the [[Ephod]] representing the [[tribe of Judah]]. According to other commentaries, however, "Nofech" means "[[garnet]]," and the "Bareqet," the stone representing the [[tribe of Levi]], is thought to be emerald.
  
 
==Famous emeralds==
 
==Famous emeralds==
  
* [[Gachala Emerald]] (origin: [[Colombia]])
+
* [[Gachala Emerald]]
* [[Chalk Emerald]] (origin: [[Colombia]])
+
* [[Chalk Emerald]]
* Duke of Devonshire Emerald (origin: [[Colombia]])
+
* Duke of Devonshire Emerald
 
* Mackay Emerald
 
* Mackay Emerald
  
 
== See also ==
 
== See also ==
  
* [[gemstone]]
+
* [[Gemstone]]
* [[mineral]]
+
* [[Mineral]]
  
== Footnotes ==
+
== Notes ==
 
<references/>
 
<references/>
  
 
== References ==
 
== References ==
*Cooper, J.C. (Ed.) (1992). ''Brewer's Myth and Legend''. New York: Cassell Publishers Ltd. ISBN 0-304-34084-7.
+
 
*Sinkankas, John (1994). ''Emerald & Other Beryls''. Geoscience Press. ISBN 0-8019-7114-4
+
* Cooper, J. C. ''Brewer's Myth and Legend.'' New York: Cassell Publishers, 1992. ISBN 0-304-34084-7
*Hurlbut, Cornelius S.; Klein, Cornelis (1985). ''Manual of Mineralogy'' (20th ed.). New York: John Wiley and Sons. ISBN 0-471-80580-7
+
* Hurlbut, Cornelius S. ''Manual of Mineralogy.'' 20th ed. New York: John Wiley, 1985. ISBN 0-471-80580-7
*Weinstein, Michael (1958). ''The World of Jewel Stones''. Sheriden House.
+
* Nassau, Kurt. ''Gems made by man.'' Carlsbad, CA: Gemological Institute of America, 1980. ISBN 0873110161; ISBN 978-0873110167
*Nassau, Kurt (1980). ''Gems made by man''. Gemological Institute of America. ISBN 0-87311-016-1
+
* Schumann, Walter. ''Gemstones of the World.'' Rev. ed. New York: Sterling Publishing, 2000. ISBN 0806994614; ISBN 978-0806994611
*Ali, Saleem H. (2006). The Emerald City: Gemstone mining in Brazil [http://www.gemecology.org]
+
* Sinkankas, John. ''Emerald & Other Beryls.'' Tucson, AZ: Geoscience Press, 1994 (original 1981). ISBN 0-8019-7114-4
*World Bank: CASM Initiative [http://www.casmsite.org]
+
* Sofianides, Anna S. ''Gems & Crystals.'' London: Parkgate Books, 1997.  
 +
* Weinstein, Michael. ''The World of Jewel Stones.'' New York: Sheridan House, 1967.
  
 
[[Category:Physical sciences]]
 
[[Category:Physical sciences]]
 
[[Category:Earth sciences]]
 
[[Category:Earth sciences]]
 
[[Category:Geology]]
 
[[Category:Geology]]
 +
[[Category:Minerals]]
  
{{credit|95218135}}
+
{{credits|95218135}}

Latest revision as of 15:17, 31 December 2021

Emerald
Emerald specimen with matrix.jpg
Emerald with host rock
General
CategoryMineral
Chemical formulaBeryllium aluminum silicate with chromium, Be3Al2(SiO3)6::Cr
Identification
ColorGreen
Crystal habitHexagonal Crystals
Crystal systemHexagonal
CleavagePoor Basal Cleavage (Seldom Visible)
FractureConchoidal
Mohs Scale hardness7.5 - 8.0
LusterVitreous
Refractive index1.576 - 1.582
PleochroismDistinct, Blue-Green/Yellow-Green
StreakWhite
Specific gravity2.70 - 2.78

Emerald (from the Greek word smaragdos, through the French esmeralde, meaning "green gemstone") is a green variety of the mineral beryl and is among the most valuable gemstones in the world. Harder than quartz but softer than diamond, the emerald usually contains many inclusions trapped during its formation. In mineralogy, an "inclusion" is any material trapped within a mineral during its formation. Synthetic emeralds that appear similar to the natural crystals are also being produced.

Although the possession of emeralds is indicative of wealth and luxury, we need to bear in mind that these (and other) gemstones were recovered by the hard labor of miners working under difficult circumstances, often placing their lives in danger.

Formation and occurrence

The Gachala Emerald, at 858 carats, is one of the largest gem emeralds in the world. It was found in 1967 at the La Vega de San Juan mine in Gachalá, Colombia.

It is thought that the elemental constituents of emerald were brought together during such geological processes as orogenesis (mountain building), metamorphism (a solid-state recrystallization of the rock) based on changes in heat, pressure, and the introduction of fluids, and land erosion. Later, crystals of the gemstones were formed. Each natural crystal retains a number of "flaws"—such as crystalline inclusions, bubbles, and fissures—that are a result of the geological processes by which it was formed.

Emeralds in antiquity were mined by the people of Egypt, Austria, and northern Pakistan.[1] Today, Colombia leads the world in terms of the number and size of emerald deposits found. In addition, quality emeralds are found in Brazil, Zambia, Zimbabwe, Madagascar, Pakistan, Afghanistan, India, and Russia.

A rare type of stone known as a "trapiche emerald" is occasionally found in the mines of Colombia. A trapiche emerald contains rays of dark carbon impurities that produce a six-pointed starlike pattern. It is named for the trapiche, a grinding wheel used to process sugarcane in the region.[2]

Characteristics

The mineral beryl consists of beryllium aluminum silicate (Be3Al2(SiO3)6), and the emerald variety is colored green by the presence of traces of chromium or vanadium, and sometimes iron. The color varies in shades of green and bluish green. In addition, emeralds come in a wide spectrum of clarity, along with various numbers of inclusions.

The emerald has a hexagonal crystal structure and a hardness of about 7.5 on the 10-point Mohs scale of hardness. This hardness rating decreases, however, with an increase in the number of inclusions in the stone. Most emeralds have many inclusions, and it is rare to find an emerald with only minor inclusions. Consequently, the toughness (resistance to breakage) is generally rated as poor.

Most emeralds are oiled as part of the post-lapidary process. The amount of oil entering an emerald microfissure is roughly equivalent to the size of a period in print.

Synthetic emeralds

Emerald showing its hexagonal structure.

The rarity and value of emerald has provided the incentive for developing synthetic emeralds. Synthetics have been produced by "flux-growth" and "hydrothermal" processes, including a method for producing an emerald overgrowth on colorless beryl.

The first commercially successful process for synthetic emeralds was that of Carroll C. Chatham. Stones produced by this process do not contain water but have traces of molybdenum and vanadium, indicating that a lithium vanadate flux process was probably used. Pierre Gilson Sr. has been the other large producer of flux emeralds, which 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 millimeter (mm) per month, and a typical seven-month growth run produces emerald crystals with a thickness of 7 mm (Nassau, 1980).

Hydrothermal synthetic emeralds have been attributed to IG-Farben, Nacken, Chatham, and others, but the first satisfactory commercial product was that of Johann Lechleitner of Inbruck, Austria. These stones, which appeared on the market in the 1960s, were initially sold under the names "Emerita" and "Symeralds" and were grown as a thin layer of emerald on top of natural, colorless beryl stones. Although not much is known about the original process, it is assumed that Lechleitner emeralds were grown in acidic conditions. Later, from 1965 to 1970, the Linde Division of Union Carbide produced completely synthetic emeralds by hydrothermal synthesis. According to their patents (US3,567,642 and US3,567,643), acidic conditions are essential to prevent chromium (the colorant) from precipitating. Typical growth conditions include pressures of 700-1400 bars at temperatures of 500 to 600 °C, with a temperature gradient of 10 to 25 °C. Growth rates as fast as 1/3 mm per day can be attained.

Flux-grown synthetic emeralds fluoresce a dull red when examined with long-wave ultraviolet light because of an indicator added during the process of synthesis. Natural specimens, by contrast, do not fluoresce in this manner.

A synthetic emerald may be referred to as "created." Its chemical and gemological composition is exactly equivalent to that of its natural counterpart. The Federal Trade Commission (FTC) has strict regulations about what can and cannot be called "synthetic" stone. The FTC states: " [created stone must have] essentially the same optical, physical, and chemical properties as the stone named."[3]

Furthermore, all natural emeralds (except for the red bixbite beryls of Utah, which are anhydrous) have water inclusions, as they are of hydrothermal origin. Likewise, hydrothermally grown synthetic emeralds contain water molecules. On the other hand, flux-grown synthetic emeralds contain no water. For this reason, flux-grown emeralds are more stable when subjected to high temperatures. In addition, wispy, veil-like inclusions are common in flux-grown synthetic emeralds.

Historical usage and trivia

  • Emeralds have been highly valued since ancient times. For instance, the Aztecs and Incas of South America considered these gems holy. In addition, the Hindu scriptures known as the Vedas assert that emeralds promise good luck and enhance well-being.[4]
  • The green of the emerald has been taken as symbolic of spring and life itself. It is also a holy color for the Islamic faith.
  • Emerald is regarded as the birthstone for April and May, as well as the traditional gemstone for the astrological sign of Taurus.
  • In some cultures, the emerald is the traditional gift for the 55th wedding anniversary. It is also used as a 20th and 35th wedding anniversary stone.
  • According to Rebbenu Bachya, the Hebrew word "Nofech" in Exodus 28:18 means "Emerald," and was the stone on the Ephod representing the tribe of Judah. According to other commentaries, however, "Nofech" means "garnet," and the "Bareqet," the stone representing the tribe of Levi, is thought to be emerald.

Famous emeralds

  • Gachala Emerald
  • Chalk Emerald
  • Duke of Devonshire Emerald
  • Mackay Emerald

See also

Notes

  1. Giuliani, Gaston, et.al. “Oxygen Isotopes and Emerald Trade Routes Since Antiquity.” Science, January 28, 2000, pp. 631-633.
  2. Davidson, Michael W. Emerald Retrieved May 17, 2007.
  3. The Federal Trade Commission, Guide for the Jewelry Industry Retrieved May 17, 2007.
  4. International Colored Gemstone Association, Emerald Retrieved May 17, 2007.

References
ISBN links support NWE through referral fees

  • Cooper, J. C. Brewer's Myth and Legend. New York: Cassell Publishers, 1992. ISBN 0-304-34084-7
  • Hurlbut, Cornelius S. Manual of Mineralogy. 20th ed. New York: John Wiley, 1985. ISBN 0-471-80580-7
  • Nassau, Kurt. Gems made by man. Carlsbad, CA: Gemological Institute of America, 1980. ISBN 0873110161; ISBN 978-0873110167
  • Schumann, Walter. Gemstones of the World. Rev. ed. New York: Sterling Publishing, 2000. ISBN 0806994614; ISBN 978-0806994611
  • Sinkankas, John. Emerald & Other Beryls. Tucson, AZ: Geoscience Press, 1994 (original 1981). ISBN 0-8019-7114-4
  • Sofianides, Anna S. Gems & Crystals. London: Parkgate Books, 1997.
  • Weinstein, Michael. The World of Jewel Stones. New York: Sheridan House, 1967.

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