Emerald
Emerald crystal from Muzo, Colombia
General
Category	Beryl variety
Chemical formula	Be3Al2(SiO3)6
Crystal symmetry	(6/m 2/m 2/m) – Dihexagonal Dipyramidal
Unit cell	a = 9.21 Å, c = 9.19 Å; Z = 2
Identification
Molar mass	537.50
Color	Green shades
Crystal habit	Massive to well Crystalline
Crystal system	Hexagonal (6/m 2/m 2/m) Space group: P6/mсc
Cleavage	Imperfect on the [0001]
Fracture	Conchoidal
Mohs scale hardness	7.5–8
Luster	Vitreous
Streak	White
Diaphaneity	Transparent to opaque
Specific gravity	Average 2.76
Optical properties	Uniaxial (-)
Refractive index	nω = 1.564–1.595, nε = 1.568–1.602
Birefringence	δ = 0.0040–0.0070
Ultraviolet fluorescence	None (some fracture filling materials used to improve emerald's clarity do fluoresce, but the stone itself does not)
References	[1]

Emerald is a variety of the mineral beryl (Be₃Al₂(SiO₃)₆) colored green by trace amounts of chromium and sometimes vanadium.^[2] Beryl has a hardness of 7.5–8 on the 10 point Mohs scale of mineral hardness.^[2] Most emeralds are highly included, so their toughness (resistance to breakage) is classified as generally poor.

Etymology[link]

The word "Emerald" is derived (via Old French: Esmeraude and Middle English: Emeraude), from Vulgar Latin: Esmaralda/Esmaraldus, a variant of Latin Smaragdus, which originated in Greek: σμάραγδος (smaragdos; "green gem"); its original source being either the Hebrew word אזמרגד izmargad meaning "emerald" or "green"^[3] or the Sanskrit word मरकत marakata meaning "emerald." The name could also be related to the Semitic word baraq (בָּרָק ;البُراق; "lightning" or "shine") (cf. Hebrew: ברקת bareqeth and Arabic: برق barq "lightning"). It is the same source for the names Persian (زمرّد zomorrod), Turkish (zümrüt), Sanskrit (मरकत ; marakata), Kannada (ಪಚ್ಚೆ ; Pacche), Telugu (Paccha), Georgian (ზურმუხტი; zurmukhti), Russian (изумруд; izumrud)^[4] and Armenian zmruxt.

Properties determining value[link]

Cut emeralds

Emeralds, like all colored gemstones, are graded using four basic parameters – the four Cs of Connoisseurship: Color, Cut, Clarity and Crystal. The last C, crystal is simply used as a synonym that begins with C for transparency or what gemologists call diaphaneity. Before the 20th century, jewelers used the term water as in "a gem of the finest water"^[5] to express the combination of two qualities, color and crystal. Normally, in the grading of colored gemstones, color is by far the most important criterion. However, in the grading of emerald, crystal is considered a close second. Both are necessary conditions. 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 gem.^[6]

In the 1960s the American jewelry industry changed the definition of 'emerald' to include the green vanadium-bearing beryl as emerald. As a result, vanadium emeralds purchased as emeralds in the United States are not recognized as such in the UK and Europe. In America, the distinction between traditional emeralds and the new vanadium kind is often reflected in the use of terms such as 'Colombian Emerald.'^[7]

Color[link]

Scientifically speaking, color is divided into three components: hue, saturation and tone. Emeralds occur in hues ranging from yellow-green to blue-green, with the primary hue necessarily being green. Yellow, blue, and red — the hues found adjacent to green on the spectral color wheel — are the normal secondary hues found in emeralds. Only gems that are medium to dark in tone are considered emerald; light-toned gems are known instead by the species name green beryl. In addition, the hue of an emerald must be bright (vivid). Gray is the normal saturation modifier or mask found in emerald; a grayish-green hue is a dull green.

Clarity[link]

Emerald tends to have numerous inclusions and surface breaking fissures. Unlike diamond, where the loupe standard, i.e. 10X magnification, is used to grade clarity, emerald is 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", to enhance the apparent clarity. 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.^[6] This relative crystal non-uniformity makes emeralds more likely than other gemstones to be cut into cabochons, rather than faceted shapes.

Treatments[link]

Most emeralds are oiled as part of the post lapidary process, in order to improve their clarity. Cedar oil, having a similar refractive index, is often used in this generally accepted practice. Other liquids, including synthetic oils and polymers with refractive indexes close to that of emerald such as Opticon are also used. The U.S. Federal Trade Commission requires the disclosure of this treatment when a treated emerald is sold.^[8] The use of oil is traditional and largely accepted by the gem trade. Other treatments, for example the use of green-tinted oil, are not acceptable in the trade. The laboratory community has recently standardized the language for grading the clarity of emeralds. Gems are graded on a four step scale; none, minor, moderate and highly enhanced. Note that these categories reflect levels of enhancement not clarity. A gem graded none on the enhancement scale may still exhibit visible inclusions. Laboratories tend to apply these criteria differently. Some gem labs 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 materially improve the look of the gemstone.

Given that the vast majority of all emeralds are treated as described above, and the fact that two stones that appear visually similar may actually be quite far apart in treatment level and therefore in value, a consumer considering a purchase of an expensive emerald is well advised to insist upon a treatment report from a reputable gemological laboratory. All other factors being equal, a high quality emerald with an enhancement level of moderate should cost half an identical stone graded none.^[6]

Emerald localities[link]

Spanish emerald and gold pendant exhibited at Victoria and Albert Museum.

Emeralds in antiquity^[when?] were mined by the Egyptians and in India and Austria.^[9]

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.^{[citation needed]} Emeralds come from three main emerald mining areas in Colombia: Muzo, Coscuez, and Chivor.^[10]

The emerald deposits of Zambia in the Kafubu River area about 45 km southwest of Kitwe produced around 20% of world production of gem quality emeralds in 2004. The mines of the Kafubu area rank second in worldwide production after Colombia.^[11]

Emeralds are also found in other countries, such as Afghanistan, Australia, Austria, Brazil,^[12] Bulgaria, Cambodia, Canada, China, Egypt, Ethiopia, France, Germany, India, Italy, Kazakhstan, Madagascar, Mozambique, Namibia, Nigeria, Norway, Pakistan, Russia, Somalia, South Africa, Spain, Switzerland, Tanzania, United States, Zambia and Zimbabwe.^[1] In the US, emeralds have been found in Connecticut, Montana, Nevada, North Carolina and South Carolina.^[1] In 1998 emeralds were discovered in the Yukon.^{[citation needed]}

Synthetic emerald[link]

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 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 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 1 mm per month, a typical seven-month growth run producing emerald crystals of 7 mm of thickness.^[13] Gilson sold his production laboratory to a Japanese firm in the 1980s, but production has ceased since; so did Chatham's, after the 1989 San Francisco earthquake.

Hydrothermal synthetic emeralds have been attributed to IG Farben, Nacken, Tairus, and others, but the first satisfactory commercial product was that of Johann Lechleitner of Innsbruck, Austria, which appeared on the market in the 1960s. These stones were initially sold under the names "Emerita" and "Symeralds", and they were grown as 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 in acid conditions.^{[citation needed]} Later, from 1965 to 1970, the Linde Division of Union Carbide produced completely synthetic emeralds by hydrothermal synthesis. According to their patents,^[14][15] 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 in Russia. They have succeeded to synthesize emeralds that have similar chemical composition as emeralds in alkaline deposits in Colombia, hence they are called “Colombian Created Emeralds” or “Tairus Created Emeralds”.^[16] Luminescence in ultraviolet light is considered a supplementary test when making a natural vs. synthetic determination, as many, but not all, natural emeralds are inert to ultraviolet light. Many synthetics are also UV inert.^[17]

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 "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."^[18]

Emerald in different cultures, and emerald lore[link]

The Gachala Emerald is one of the largest gem emeralds in the world, at 858 carats (172 g). This stone was found in 1967 at La Vega de San Juan mine in Gachalá, Colombia. It is housed at the National Museum of Natural History of the Smithsonian Institution in Washington, D.C.

Emerald is regarded as the traditional birthstone for May, as well as the traditional gemstone for the astrological signs of Taurus, Cancer and sometimes Gemini. One of the quainter anecdotes on emeralds was by the 16th-century historian Brantôme, who referred to the many impressive emeralds the Spanish under Cortez had brought back to Europe from Latin America. On one of Cortez's most notable emeralds he had the text engraved Inter Natos Mulierum non sur-rexit mayor ("Among those born of woman there hath not arisen a greater," Matthew 11:11) which referred 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 of an extremely precious pearl (to which he dedicated a work, A beautiful and incomparable pearl), and even for the death of King Charles IX of France, who died soon after.^[19] "The Attenbury Emeralds" is a detective story in which Lord Peter Wimsey must solve several emerald-related mysteries.

Notable emeralds[link]

Gallery[link]

• 

  Left to right: The Indian Emerald Necklace, the Gachala Emerald crystal and the Mackay Emerald Necklace (167-carat center stone), all pieces from the U.S. National Museum of Natural History.

• 

  The Chalk Emerald ring, containing a top-quality 37-carat emerald, also in the U.S. National Museum of Natural History.

• 

  The Hooker Emerald Brooch, containing a 75-carat square-cut emerald, also in the U.S. National Museum of Natural History.

• 

  Emerald crystal (about 1 cm) in calcite matrix, Muzo, Colombia.

• 

  A 5-carat emerald from Muzo.

• Emerald2.JPG

  Typical low quality emerald.

See also[link]

• List of minerals

References[link]

Further reading[link]

• 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
• Hurlbut, Cornelius S.; Klein, Cornelis (1985). Manual of Mineralogy (20th ed.). New York: John Wiley and Sons. ISBN 0-471-80580-7
• Weinstein, Michael (1958). The World of Jewel Stones. Sheriden House.
• Ali, Saleem H. (2006). The Emerald City: Emerald mining in Brazil (+Gemstone mining in other countries) http://www.uvm.edu/envnr/gemecology/brazil.html
• Ball, V., & Crooke, W., Travels In India by Jean-Baptiste Tavernier, Oriental Reprint Corporation, New Delhi, India. Online version Tavernier's travels in India
• Wise, Richard W., Secrets Of The Gem Trade, The Connoisseur’s Guide To Precious Gemstones, Brunswick House Press

External links[link]

Wikimedia Commons has media related to: Emeralds

• ICA's Emerald Page International Colored Stone Emerald Page
• Webmineral Beryl Page Webmineral with crystallographic and mineralogical information
• Richard W. Wise: GemWise: The Emeralds of Colombia Parts 1–4: http://www.rwwise.com/tec2.html

This biographical article needs additional citations for verification. Please help by adding reliable sources. Contentious material about living persons that is unsourced or poorly sourced must be removed immediately, especially if potentially libelous or harmful. (May 2012)

Caro Emerald
Emerald singing in Broek op Langedijk, Netherlands
Background information
Birth name	Caroline Esmeralda van der Leeuw
Born	(1981-04-26) 26 April 1981 (age 31) Amsterdam, Netherlands
Genres	Jazz, easy listening
Occupations	Musician
Instruments	Vocals
Years active	2007-present
Labels	Grandmono Records
Website	www.caroemerald.com

Caroline Esmeralda van der Leeuw (b. 26 April 1981 in Amsterdam), best known by her stage name, Caro Emerald, is a Dutch jazz singer. She debuted on 6 July 2009 with her single "Back It Up". Her debut album Deleted Scenes from the Cutting Room Floor set a new all-time chart record on 20 August 2010, spending its 30th week at number one on the Dutch album chart, beating the previous record set by Michael Jackson's Thriller by one week.^[1] The album has become the biggest selling album of 2010 in the Netherlands, selling over 300,000 copies so far. In total more than a million copies have been sold so far. On 3 October 2010, Van der Leeuw was awarded the Dutch Music Prize "Edison Award" for Best Female Artist.^[2]

Biography[link]

Caroline Esmeralda van der Leeuw was born on 26 April 1981 in Amsterdam, the Netherlands.^[3] She was trained as a jazz vocalist at the Amsterdam Conservatory, graduating in 2005.

Music career[link]

In early 2007 Dutch producer Jan van Wieringen invited van der Leeuw to sing the vocal on a demo track he was co-producing with songwriter/producer David Schreurs. The song, "Back It Up", had been written by Schreurs together with Canadian songwriter Vince Degiorgio, and was based on a hip-hop beat created by Jan and Robin Veldman. Caro's jazzy vocal style was considered a "perfect match" for the new song.^[4]

The song demo was pitched to various publishers and labels but although the reaction was positive they struggled to imagine it suiting any particular artist and didn't believe it had a strong enough chart potential.^[4] In the meantime, however, the song was posted on YouTube reaching public notice around the world. Radio stations picked it up, and the song gained popularity.

When Degiorgio, Schreurs, and van Wieringen discovered van der Leeuw's sound had such potential, they set about working on a full album presenting Caro Emerald as the star in the summer of 2008 and used "Back It Up"'s mix of 40s-50s jazz, easy listening, orchestral Latin, combined with infectious beats as a model.^[4] Adopting a sample based approach but with live instrumentation, the writing sessions drew from a wide range of influences including jazz organist Jackie Davis, exotica composer Martin Denny, mambo king Perez Prado, 20s/30s jazz and van der Leeuw's own vocal inspirations of The Andrews Sisters, Billie Holiday and Sarah Vaughan.^[4] The usual method would be for Schreurs to produce the backing tracks at home and then get together with top line writer and lyricist Degiorgio to write the song. Van der Leeuw would occasionally pitch in her own melody and lyrical ideas, and Van Wieringen co-created the tracks for "The Other Woman" and "Dr Wanna Do".^[4]

After the record labels they approached failed to sign van der Leeuw, Schreurs, van Wieringen and van der Leeuw created their own label Grandmono Records and released "Back It Up" as the first single on 6 July 2009. It was an instant hit and listed in the Dutch Top 40 for 12 weeks, peaking at #12. Kraak & Smaak provided a remix of the song. "Back It Up" was the most played song on Dutch radio station 3FM in 2009.^[5]. Follow up A Night Like This became a #1 hit in The Netherlands.

In 2011 Emerald recorded a version of Brook Benton's 1963 hit "You're All I Want for Christmas", sampling the original song to produce a duet with Benton, who died in 1988. The song was released in December 2011.^[6]

On New Years Eve 2011/2012 Emerald appeared on BBC Two television on the Jools Holland Hootenanny show backed by the Jools Holland Rhythm & Blues Orchestra.

Early 2012, Caro Emerald won two prestigious German awards: a Goldene Kamera for Best Musik International and an Echo Award for Best Newcomer International, beating out other Echo nominees who included Lana Del Rey, Gotye, and LMFAO.

Debut album[link]

Emerald singing in the Netherlands on 9 July 2010

Van der Leeuw's debut album Deleted Scenes from the Cutting Room Floor was released on 29 January 2010 and immediately occupied the number 1 position of the Dutch Album Top 100 charts. On 20 August 2010, the album had been number 1 for 27 weeks, an all time record, beating Michael Jackson's Thriller, which spent 26 weeks at number one in 1983.^[1] The album reached double platinum status in the Netherlands on 5 July 2010.^[7] In August 2010 it reached triple platinum.^[1], in November 2010 four times platinum (200.000)^[8] and in december 2011, six platinum (over 300.000 albums sold). Deleted Scenes From The Cutting Room Floor spent 104 weeks in the official Album charts, until it was removed due to a Dutch chart rule which provided that albums can't spend more than 2 years in the charts.

The second single from the album was "A Night like This". The song was listed in the Dutch Top 40 for 26 weeks and peaked at number 2. In the national single charts, the song peaked at number 1. It was the most played song in The Netherlands in 2010.

The cinematic and upbeat sound of the album has resulted in frequent use of the songs in TV series and advertising campaigns around the world. "A Night Like This" featured in the trailer campaign of NBC series The Playboy Club, a brand campaign by Martini, the trailer of 2 Days in New York (starring Chris Rock and Julie Delpy), and The Secret Circle, amongst others. "Back it Up" featured in a TV ad for Wind Mobile. "That Man" featured in Dancing with the Stars, The Vampire Diaries, a UK advertising campaign for Sky TV, and has been incorporated in the original score of the Disney Nature film Chimpanzee.

On 15 January 2011, she won the Popprijs 2010 for best Dutch pop act of 2010.^{[citation needed]} Also in 2011, the album was released throughout Europe with great commercial success. Deleted Scenes From The Cutting Room Floor became a hit in the UK (1x platinum with sales exceeding 360.000, 8 weeks top 10 peaking at #4), Germany (1x platinum with sales exceeding 280.000, peaking at #5 and Platinum single for A Night Like This with sales exceeding 340.000), Poland (6x platinum), Italy (Gold Single for "Back it Up"), abd Austria (#1 with A Night Like This) In the UK, all 6 singles and even the entire album were A-listed by radio station BBC2. Over 1.000.000 albums have been sold worldwide (certified IFPI Platinum).^{[citation needed]} Due to it's exceptional success, the album was included in an episode of the Dutch version of Classic Albums in April 2012.^{[clarification needed]} In May 2012, Emerald was offered a contract record by Universal Music Group in the USA.

Awards[link]

• 11 April 2010: 3FM Serious Talent Award
• April 15, 2010: Schaal van Rigter
• April 26, 2010: De Eerste Prijs
• Oktober 3, 2010: Edison Best female singer
• MTV EMA Award for best Dutch and Belgian Act.
• January 12, 2011: European Border Breakers Award 2011
• January 15, 2011: 3FM Mega Award 2010
• January 15, 2011: Popprijs 2010
• March 3, 2011: Zilveren Harp 2010
• March 3, 2011: Het Beste Nederlandse lied 2010 (Best song of the year 2010)
• March 14, 2011: 3FM Awards: Best Album and Beste Female Singer
• June 12, 2011: TMF Award for best female
• Februari 4, 2012: Goldene Kamera 2012 Best Music International
• March 2012, Echo (music award) Award Best International Newcomer

^{[9][10][11][12][13][14]}

Discography[link]

Albums[link]

Singles[link]

References[link]

External links[link]

Wikimedia Commons has media related to: Caro Emerald

• Official website
• Official Uvumi Profile
• Caro Emerald Profile and Discography on This is Vintage Now