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Aquamarine (gem)

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Aquamarine
Aquamarine on muscovite
General
CategorySilicate minerals, beryl variety
Formula
(repeating unit)		Be3Al2Si6O18
Identification
ColorPale blue to light green
FractureConchoidal
Mohs scale hardness7.5–8
StreakWhite[1]
DiaphaneityTransparent to translucent
Specific gravity2.65–2.85
Refractive index1.57-1.59

Aquamarine is a pale-blue to light-green variety of the beryl family,[2] with its name relating to water and sea.[3] The color of aquamarine can be changed by heat, with a goal to enhance its physical appearance (though this practice is frowned upon by collectors and jewelers).[4] It is the birth stone of March.[5]

Aquamarine is a fairly common gemstone,[6] rendering it more accessible for purchase, compared to other gems in the beryl family.[7] Overall, its value is determined by weight, color,[5] cut, and clarity.[8]

It is transparent to translucent and possesses a hexagonal crystal system.[9] Aquamarine mainly forms in granite pegmatites and hydrothermal veins,[10] and it is a very lengthy process that can take millions of years to form.[9]

Aquamarine occurs in many countries over the world, and is most commonly used for jewelry, decoration and its properties.[11]

Aquamarine is mainly extracted through open-pit mining, however underground mining is also a possibility to access aquamarine reserves.[12]

Aquamarine is a durable gemstone, but it is highly recommended to conserve it on its own to prevent damage/scratches.[9]

Famous aquamarines include the Dom Pedro, the Roosevelt Aquamarine, the Hirsch Aquamarine, Queen Elizabeth's Tiara, Meghan Markle's ring, and the Schlumberger bow.[13]

Name and etymology

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The name aquamarine comes from aqua (Latin for 'water'), and marine, deriving from marina (Latin for 'of the sea').[3] The word aquamarine was first used in the year 1677.[14][10]

The word aquamarine has been used as a modifier for other minerals like aquamarine tourmaline, aquamarine emerald, aquamarine chrysolite, aquamarine sapphire, or aquamarine topaz.[15]

Physical properties

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Crystal structure of Aquamarine

Aquamarine is blue with hues of green, caused by trace amounts of iron found within the crystal structure. It can vary from pale to vibrant and transparent to translucent. Better transparency in aquamarine gemstones means that light may go through the crystal with less interference. The hexagonal crystal system is where aquamarine crystallizes. It forms prismatic crystals with a hexagonal cross-section.[9][16] These crystals can be microscopic to enormous in size and frequently feature faces with vertical striating. The lustre of aquamarine ranges from vitreous to resinous. It can have a glass-like brilliance and a sheen when cut and polished correctly.[9]

Chemical composition

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Aquamarine has a chemical composition of Be3Al2Si6O18,[5] also containing Fe2+.[17] It belongs to the beryl family, being a beryllium aluminum silicate mineral. It is closely related to emerald, morganite, and heliodor. Aquamarine is chemically stable and resistant to most common chemicals and acids.[9] It has a hardness of 7.5–8 on the Mohs scale.[18][16] While aquamarine often contains no inclusions,[19] it may possess them, with content such as mica, hematite, saltwater, biotite, rutile or pyrite.[15] Its hardness on the Mohs scale of mineral hardness is rated as 7.5-8.[16] This rating gives aquamarine the chance to be a very suitable gem for everyday wear.[9]

Geological formation

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Aquamarine mainly forms in granite pegmatites (coarse-grained igneous rock) and hydrothermal vents. The remaining liquid that is left behind after granitic magma crystallizes is what gives rise to pegmatites.[10][9] The residual fluids, which are rich in volatile elements and minerals such as silicon, aluminum, and beryllium, concentrate when the magma cools and solidifies.[9]

Aquamarine found in granite pegmatite

Aquamarine may also be formed by hydrothermal fluids, which are hot, mineral-rich solutions. These liquids contain dissolved minerals and metals as they move through fissures and cavities in the crust of the Earth. Fractures, faults, and veins are just a few of the geological environments that hydrothermal systems can be linked to.[9]

Beryllium is a necessary component for the production of aquamarine, a type of beryl. Although beryllium is a relatively uncommon element in the crust of the Earth, it can be found in concentrated forms in some geological settings. These include beryllium-rich hydrothermal systems and granite pegmatites, which contain large amounts of beryllium-bearing minerals.[9]

The dissolved elements start to precipitate out of the solution and form crystals as the hydrothermal fluids cool and come into contact with the right minerals and circumstances. Crystals of beryl, which include aquamarine, begin to form in pegmatite veins and host rock fissures or cavities. Aquamarine crystals grow over long periods, which enables them to take on their distinctive hexagonal prismatic shape.[9]

This is a very long process that can take millions of years to form. The settings in which aquamarine forms can vary and may lead to variations in gem quality, size, and color.[9]

Value

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Queen Elizabeth II wearing the Brazilian Aquamarine Parure in 2006. The star and collar are a Brazilian decoration, the Order of the Southern Cross.

The value of aquamarine is determined by its weight, color,[5] cut, and clarity.[8] Due to its relative abundance, aquamarine is comparatively less expensive than other gemstones within the beryl group, such as emerald or bixbite (red beryl), however it is typically more expensive than similarly colored gemstones such as blue topaz.[19][6] Maxixe is a rarer variant of aquamarine, with its deep blue coloration,[19] however, its color can fade due to sunlight.[1] The color of maxixe is caused by NO3.[20] Dark-blue maxixe color can be produced in green, pink or yellow beryl by irradiating it with high-energy radiation (gamma rays, neutrons or even X-rays).[21] Naturally occurring blue hued aquamarine specimens are more expensive than those that have undergone heat treatment to reduce yellow tones caused by ferric iron.[6] Cut aquamarines that are over 25 carats will have a lower price per carat than smaller ones of the same quality.[22] Overall, the quality and color will vary depending on the source of the gem.[9]

In culture

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Aquamarine stone in a silver pendant

Aquamarine is the birth stone for the month of March.[5] It has historically been used a symbol for youth and happiness due to its color, which has also, along with its name, made Western culture connect it with the ocean.[23][22] Ancient tales have claimed that aquamarine came from the treasure chests of mermaids; which led to sailors using this gemstone as a lucky charm to protect against shipwreck.[24] Additionally, ancient Romans believed this stone had healing properties, due to the stone being almost invisible when submerged in water.[7][10]

The Chinese used it to make seals, and showpiece dolls.[25] The Japanese used it to make netsuke.[26]

Portrait of Julia Domma carved into aquamarine in 1942. (Intaglio)

The Egyptians, Greeks, Hebrews, and Sumerians all believed that aquamarine stones were worn by the High Priest of the Second Temple. It was said that these stones were engraved to represent the six tribes of Israel. Greeks also engraved designs into aquamarine 2 thousand years ago and turned them into intaglios.[27]

In our modern era, aquamarine is mainly used for jewelry, decoration and its properties.[11] It can be cut and shaped into rings, earrings, necklaces, and bracelets.

Aquamarine became a state gem for Colorado in 1971.[28]

Occurrence

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Aquamarine of 15,256 carats from Minas Gerais, Brazil

Aquamarine can be found in countries like Afghanistan, China, Kenya, Pakistan, Russia, Mozambique, the United States,[29] Brazil, Nigeria, Madagascar, Zambia, Tanzania, Sri Lanka,[30] Malawi, India,[5] Zimbabwe, Australia, Myanmar, and Namibia.[31] The state of Minas Gerais is a major source for aquamarine.[6]

Aquamarine can mostly be found in granite pegmatites.[6] It can also be found in veins of metamorphic rocks that became mineralized by hydrothermal activity.[5]

Dom Pedro aquamarine in the National Museum of Natural History, Washington, D.C.

The largest known example is the Dom Pedro aquamarine found in Pedra Azul, Minas Gerais, Brazil, in the late 1980's. It weighs roughly 4.6 pounds, cut from a 100-pound aquamarine crystal, and measures 10,363 carats. It resides in the National Museum of Natural History in Washington.[32]

Mining and extraction

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The initial stages of the aquamarine mining process involve prospecting and exploration. Finding prospective locations or regions with aquamarine reserves is necessary. Geological mapping, remote sensing, mapping, remote sensing, sampling,[12] and other methods are used by geologists and mining firms to locate potentially aquamarine-containing geological formations and structures. Preparation of the site is the next step, which includes removing any vegetation, leveling the land, and constructing the facilities - such as access roads and workspaces. It is possible to mine aquamarine using both open-pit and underground techniques. This will depend on the size of the operation, the features of the deposit, and environmental conditions.[9]

The most popular technique for extracting aquamarine on a large scale is open-pit mining.[12] In order to reveal the aquamarine-bearing ore, the soil, vegetation, and rock cover must be removed. The ore is extracted using trucks, bulldozers, and excavators, to remove the material.[9]

Underground mining may occasionally be used to obtain aquamarine reserves. This process entails digging shafts and tunnels[12] to reach the ore bodies or veins that contain gems. When the aquamarine deposit is deep or the surrounding rock is too hard for open-pit extraction, underground mining is used, even though it can be more difficult and expensive than open-pit mining.[9]

After extraction, the ore containing aquamarine is delivered to a processing plant. To extract the aquamarine crystals from the surrounding rock and other minerals, the ore is crushed, processed, and occasionally cleaned. The aquamarine can be concentrated and purified using a variety of methods, such as magnetic separation, froth flotation, and gravity separation.[9]

The aquamarine crystals are then sorted according to size, shape, color, and clarity following the initial processing. The gemstones are assessed and graded by gemologists and experts according to predetermined standards, such as the four C's (color, clarity, cut, and carat weight). Only the best aquamarine crystals are chosen to be used in jewelry made of gemstones.[9]

Care and maintenance

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Aquamarine is classified as a durable gem, however, it may still be damaged. In storage, it is advised to place it on its own, without the interruption of other gemstones to prevent scratches. Warm soapy water and a soft brush are the best ways to clean this gemstone, however, ultrasonic cleaners are relatively safe for aquamarine.[9]

Alternative uses

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Although aquamarine is mainly used for jewelry,[11] aquamarine powder has proven to be a beneficial ingredient in cosmetics. It has a binding and skin protecting function that ensures protection of the skin from external influences.[33]

Notable examples

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Aquamarine Origin Size Location Description
Dom Pedro aquamarine[34] Found in Pedra Azul, Minas Gerais, Brazil. Mined in 1980.[35] 10,363 carats National Museum of Natural History, Washington, D.C.[36][37] World's largest cut aquamarine. Named after the first two emperors of Brazil, Pedro I and Pedro II.[38]
The Roosevelt Aquamarine[39] Given to Eleanor Roosevelt in 1936. 1,298 carats Franklin D. Roosevelt Presidential Library and Museum Given to US First Lady Eleanor Roosevelt when she and President Roosevelt visited Brazil. It is known as the second largest cut specimen of aquamarine, behind the Dom Pedro.[38]
The Hirsch Aquamarine Once owned by Louis XV. 109.92 carats Unknown Once owned by the French Emperor Louis XV.
Queen Elizabeth's Aquamarine Tiara Given to Queen Elizabeth in 1953. Unknown British royal family In 1957, she purchased this tiara from Garrad, to match another aquamarine set she had received from Brazilian President Getúlio Vargas in 1953 as a coronation gift.[38]
Meghan Markle's Aquamarine Ring Once owned by Princess Diana. >30 carats Meghan Markle Received from Prince Harry during their wedding, this ring once belonged to Princess Diana.[38]
The Schlumberger Bow
The Schlumberger Bow
 Owned by Tiffany & Co. 148.5 carats Field Museum of Natural History, Chicago. Was part of a collection owned by Tiffany & Co. Purchased in 1984 to be placed in the Field Museum.[13]

See also

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References

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  1. ^ a b Schumann, Walter (2006). Gemstones of the World. Sterling Publishing Company, Inc. p. 110. ISBN 978-1-4027-4016-9.
  2. ^ Manutchehr-Danai, Mohsen (2013-03-09). Dictionary of Gems and Gemology. Springer Science+Business Media. p. 24. ISBN 978-3-662-04288-5.
  3. ^ a b Cresswell, Julia (2014). Little Oxford Dictionary of Word Origins. Oxford University Press. p. 174. ISBN 978-0-19-968363-5.
  4. ^ Wenk, Hans-Rudolf; Bulakh, Andrei (April 2004). Minerals: Their Constitution and Origin. Cambridge University Press. p. 542. ISBN 978-0-521-52958-7.
  5. ^ a b c d e f g "Aquamarine: the blue gemstone and March birthstone". geology.com. Retrieved 2021-08-18.
  6. ^ a b c d e Oldershaw, Cally (2003). Firefly Guide to Gems. Firefly Books. p. 124. ISBN 978-1-55297-814-6.
  7. ^ a b Oldershaw, Cally (2003). Firefly Guide to Gems. Firefly Books. ISBN 978-1-55297-814-6.
  8. ^ a b "How to Value Aquamarine". Sciencing. 24 April 2017. Retrieved 2021-08-30.
  9. ^ a b c d e f g h i j k l m n o p q r s t MAT, Mahmut (2023-05-28). "Aquamarine | Properties, Formation, Occurrence » Gemstone". Geology Science. Retrieved 2024-03-14.
  10. ^ a b c d Cruz, Devina (2020-07-29). "How Aquamarine Is Formed: Find Out The Process Behind It". Medium. Retrieved 2024-03-14.
  11. ^ a b c "Top 5 Benefits and Facts of Aquamarine Gemstones - Fine Art Minerals". 2023-04-05. Retrieved 2024-03-06.
  12. ^ a b c d "Mining and Extraction of Aquamarine". Natural Gems Belgium. 2024-02-16. Retrieved 2024-03-14.
  13. ^ a b "Field Museum's "Crane Pacific Expedition" | Classic Chicago Magazine". classicchicagomagazine.com. Retrieved 2024-03-19.
  14. ^ "aquamarine". Merriam-Webster.com Dictionary. Merriam-Webster. Retrieved 2021-08-31.
  15. ^ a b "Aquamarine | Birthstones | Gems | Geology & Soils | Online Resources | School of Natural Resources". snr.unl.edu. University of Nebraska–Lincoln. Retrieved 2021-08-30.
  16. ^ a b c "Physical and Chemical Properties of Aquamarine". Natural Gems Belgium. 2024-02-16. Retrieved 2024-03-14.
  17. ^ Perkins, Dexter; Henke, Kevin R.; Simon, Adam C.; Yarbrough, Lance D. (2019-07-24). Earth Materials: Components of a Diverse Planet. CRC Press. p. 82. ISBN 978-0-429-59119-8.
  18. ^ Jones, Cindy (2005). Geology. Lotus Press. pp. 16–17. ISBN 978-81-89093-35-8.
  19. ^ a b c Grande, Lance; Augustyn, Allison (2009-11-15). Gems and Gemstones: Timeless Natural Beauty of the Mineral World. University of Chicago Press. p. 125. ISBN 978-0-226-30511-0.
  20. ^ Manutchehr-Danai, Mohsen (2013-03-09). Dictionary of Gems and Gemology. Springer Science & Business Media. p. 307. ISBN 978-3-662-04288-5.
  21. ^ Nassau, K. (1976). "The deep blue Maxixe-type color center in beryl" (PDF). American Mineralogist. 61: 100. Archived (PDF) from the original on 26 June 2011.
  22. ^ a b "Aquamarine Value, Price, and Jewelry Information – Gem Society". International Gem Society. Retrieved 2021-09-21.
  23. ^ Pearl, Richard M. (2016-09-06). Popular Gemology. Read Books Ltd. p. 95. ISBN 978-1-4733-5633-7.
  24. ^ Webster, Richard (2012-09-08). The Encyclopedia of Superstitions. Llewellyn Worldwide. p. 14. ISBN 978-0-7387-2561-1.
  25. ^ nnexports (2022-06-23). "Moss Aquamarine: Everything You Need To Know!". Medium. Retrieved 2024-03-06.
  26. ^ Rapp, George R. (2013-03-09). Archaeomineralogy. Springer Science & Business Media. pp. 97–98. ISBN 978-3-662-05005-7.
  27. ^ "Aquamarine History". American Gem Society. Retrieved 2024-03-06.
  28. ^ Johnson, Lars W.; Voynick, Stephen M. (2021-06-08). Rockhounding for Beginners: Your Comprehensive Guide to Finding and Collecting Precious Minerals, Gems, Geodes, & More. Simon and Schuster. p. 89. ISBN 978-1-5072-1527-2.
  29. ^ Oldershaw, Cally (2003). Firefly Guide to Gems. Firefly Books. p. 125. ISBN 978-1-55297-814-6.
  30. ^ "Aquamarine Value & Worth". Grav. Retrieved 2021-08-29.
  31. ^ Grande, Lance; Augustyn, Allison (2009-11-15). Gems and Gemstones: Timeless Natural Beauty of the Mineral World. University of Chicago Press. p. 126. ISBN 978-0-226-30511-0.
  32. ^ Magazine, Smithsonian. "How the World's Largest Aquamarine Gem Came to Be". www.smithsonianmag.com. Retrieved 2024-03-06.
  33. ^ "Ingredient". COSMILE Europe. Retrieved 2024-03-21.
  34. ^ "Dom Pedro Aquamarine – Smithsonian Institution".
  35. ^ "Introducing the Dom Pedro Aquamarine".
  36. ^ Vastag, Brian (2 December 2012). "The Dom Pedro aquamarine's long and winding path to the Smithsonian". The Washington Post. Archived from the original on 8 December 2012. Retrieved 7 December 2012.
  37. ^ "Magnificent Dom Pedro aquamarine to go on view in the Smithsonian's Natural History Museum". Smithsonian Science. Smithsonian Institution. Archived from the original on 5 July 2014. Retrieved 7 December 2012.
  38. ^ a b c d "Discover the Best Aquamarine in the World". Caldera Gem. Retrieved 2024-03-19.
  39. ^ "Six Famous Aquamarines".
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