Blue diamond
{{Short description|Blue-colored variant of a diamond}}
{{Other uses|Blue diamond (disambiguation)}}
{{Infobox mineral
| name = Blue Diamond
| image = HopeDiamondwithLighting2.JPG
| imagesize =
| caption = Closeup of the Hope Diamond, a famous dark blue diamond
| category = Native minerals|
| boxbgcolor = #7da7d9
| boxtextcolor = black
|molweight = {{val|12.01|ul=g/mol}}
|strunz = 1.CB.10a
| color = Light Blue to Deep Blue
| habit = Octahedral
|system = Cubic
|class = Hexoctahedral (m{{Overline|3}}m)
H-M symbol: (4/m {{Overline|3}} 2/m)
|twinning = Spinel law common (yielding "macle")
|cleavage = 111 (perfect in four directions)
|fracture = Conchoidal (shell-like)
|mohs = 10 (defining mineral)
|luster = Adamantine
|polish = Adamantine
|refractive = 2.418 (at 500 nm)
|opticalprop = Isotropic
|birefringence = None
|dispersion = 0.044
|pleochroism = None
|streak = Colorless
|melt = Pressure dependent
|gravity = {{val|3.52|0.01}}
|density = 3.5–{{val|3.53|ul=g/cm3}}
|diaphaneity = Transparent to subtransparent to translucent
|references ={{cite web|publisher=WebMineral|title=Diamond|url=http://webmineral.com/data/Diamond.shtml|accessdate=July 7, 2009}}
}}
Blue diamond is a type of diamond which exhibits all of the same inherent properties of the mineral except with the additional element of blue color in the stone. The Mohs hardness of blue diamond is around the same as a regular diamond, with a hardness of 10. They are colored blue by trace impurities of boron within the crystalline lattice structure. Blue diamonds belong to a subcategory of diamonds called fancy color diamonds, the generic name for diamonds that exhibit intense color.
Properties determining value
The same four basic parameters that govern the grading of all gemstones are used to grade blue diamonds–the four Cs of Connoisseurship: color, clarity, cut and carat weight. Color is considered the most important criterion for grading a blue diamond and determining its value. However, the most valuable blue diamonds also exhibit the highest clarity grades.{{cite web | title=Investing In Natural Blue Diamonds| url=http://www.investments.diamonds/investing-in-natural-blue-diamonds/| website=investments.diamonds| date=15 July 2015| publisher=Diamond Investment & Intelligence Center| accessdate=18 December 2016}} There is no known blue diamond with a completely flawless (F) clarity grading, although several are known which are graded Internally Flawless (IF).{{cite web|title=Fancy Color Diamond Quality Factors|url=https://www.gia.edu/fancycoloreddiamond-quality-factor|website=GIA.edu|publisher=Gemological Institute of America|accessdate=18 December 2016}}
One of the earliest mentioned blue diamonds is the Hope Diamond, a 45.52-carat fancy dark grayish-blue which is believed to have been discovered in India but whose first recorded presence was in 1666 by French gem merchant Jean-Baptiste Tavernier, after whom it was called the Tavernier Blue. Its last owner was famed jeweler Harry Winston before he donated it to the Smithsonian National Museum of Natural History in Washington, D.C.{{cite web| title=Harry Winston: The Man Who Gave Away The Gem| url=http://www.smithsonianchannel.com/site/smithsonian/hope_winston.html| website=Smithsonian Channel| publisher=Smithsonian Institution| accessdate=18 December 2016| archive-url=https://web.archive.org/web/20090826234212/http://www.smithsonianchannel.com/site/smithsonian/hope_winston.html#| archive-date=2009-08-26| url-status=dead}} Colorless (“White”) diamonds have remained the most popular type of diamond through the millennia, but the existence of this blue diamond so long ago affirms the reality of the demand for fancy color diamonds over the years.
=Color=
In gemology,[http://gia4cs.gia.edu/EN-US/gr-colored-diamonds-gemstones.htm Grading Fancy-Color Diamonds] {{Webarchive|url=https://web.archive.org/web/20141102115539/http://gia4cs.gia.edu/en-us/gr-colored-diamonds-gemstones.htm# |date=2014-11-02 }}; Gemological Institute of America color is divided into three components: hue, saturation and tone. Blue diamonds occur in hues ranging from green-blue to gray-blue, with the primary hue necessarily being blue. Green and gray are the normal secondary hues that can be found in blue diamonds. Blue diamonds are considered most beautiful and valuable when no secondary color is present but are pure blue. However, a pure blue diamond of light color may be considered less valuable than a green-blue or gray-blue diamond whose color is more vivid. The characteristic of color is very complex in blue diamonds for this reason.
{{cite book |url=https://books.google.com/books?id=YdBMMwEACAAJ |last=Rachminov |first=E. |title= The Fancy Color Diamond Book: Facts and Secrets of Trading in Rarities |publisher= Diamond Odyssey |location=New York |year=2009 |isbn=978-9659149902}}{{cite web | title=What Are The Colors of Fancy Diamonds? | date=16 June 2016 | url=http://www.investments.diamonds/colors-fancy-diamonds/ |publisher=Diamond Investment & Intelligence Center |accessdate=18 December 2016}} Most pure blue diamonds are Type IIb, meaning they contain either very few or a complete lack of nitrogen impurities. Type Ia Blue stones contain a secondary hue and get their color from the presence of hydrogen.{{cite web |title=Blue Diamonds |url=http://www.naturallycolored.com/diamond-education/blue-diamonds-wiki |publisher=Naturally Colored |accessdate=18 December 2016 |archive-url=https://web.archive.org/web/20161225214503/http://www.naturallycolored.com/diamond-education/blue-diamonds-wiki |archive-date=25 December 2016 |url-status=dead }}
=Clarity=
As with all diamonds, the loupe standard is used to grade clarity. This means that the inclusions are judged based on the appearance of the diamond under 10x magnification, and not how it would appear to the naked eye. Unlike in colorless diamonds, the clarity in blue diamonds has little effect on the diamond’s value. The exception is when there is an especially high clarity on a very vividly colored diamond. In this case, the clarity can add tremendous value.{{cite web | title=What Are The Colors Of Fancy Diamonds? |date=16 June 2016 |url=http://www.investments.diamonds/colors-fancy-diamonds/ |publisher=Diamond Investment & Intelligence Center |accessdate=18 December 2016 }}
=Treatments=
Blue diamonds are only considered rare and valuable if they are natural. The definition of a natural blue diamond is a blue diamond that was mined with its blue color already present.{{cite web |title=Blue Diamonds |url=https://www.ncdia.com/blue.php |publisher=NCDIA |accessdate=18 December 2016 |archive-url=https://web.archive.org/web/20161120185908/http://www.ncdia.com/blue.php |archive-date=20 November 2016 |url-status=dead }} Since the 1950s, many methods have been developed to change a diamond’s appearance, including adding color to a colorless stone. These are considered enhanced diamonds and do not have a natural blue diamond value or resale value.{{cite AV media | people = The National Science Foundation & NBC Learn | title = Science Of Innovation: Synthetic Diamonds | language = English | url = https://science360.gov/obj/tkn-video/71b665e4-3637-4acb-810e-60d5ab559adf/science-innovation-synthetic-diamonds | access-date = 18 December 2016 | publisher = NBC Learn}} Enhanced blue diamonds are not bought with the intention of investment or eventual resale. Synthetic blue diamonds have also been made, using the HPHT method.{{cite web | title=Largest Blue HPHT Synthetic Diamond|url= https://www.gia.edu/gems-gemology/spring-2016-labnotes-largest-blue-hpht-synthetic-diamond|publisher=GIA |accessdate=25 December 2016}}
Blue diamond mines
The earliest recorded blue diamond, the Hope Diamond, was discovered in India, in the Kollur mine in the Guntur district of Andhra Pradesh (which at the time was part of the Golconda kingdom), in the seventeenth century.India Before Europe, C.E.B. Asher and C. Talbot, Cambridge University Press, 2006, {{ISBN|0-521-80904-5}}, p. 40A History of India, Hermann Kulke and Dietmar Rothermund, Edition: 3, Routledge, 1998, p. 160; {{ISBN|0-415-15482-0}}Deccan Heritage, H. K. Gupta, A. Parasher and D. Balasubramanian, Indian National Science Academy, 2000, p. 144, Orient Blackswan, {{ISBN|81-7371-285-9}} However, blue diamonds have also been discovered in the Cullinan Mine in South Africa and the Golconda region. A few blue diamonds have been discovered in the Argyle Mine in Western Australia as well, and are offered at their annual Argyle Tender when they are found.{{cite web | title=Blues and Violets | url=http://www.argylepinkdiamonds.com.au/blues-and-violets | publisher=Argyle Pink Diamonds | accessdate=25 December 2016 | archive-date=25 December 2016 | archive-url=https://web.archive.org/web/20161225214646/http://www.argylepinkdiamonds.com.au/blues-and-violets | url-status=dead }} It is thought that blue diamonds, unlike most other diamonds, are formed in the lower part of Earth’s mantle, and that the boron creating their blue color originates from serpentinite carried down to the mantle by subducting ocean tectonic plates.{{cite web | title=Rare blue diamonds are born deep in Earth's mantle |date=August 2018 |url=https://www.sciencenews.org/article/rare-blue-diamonds-are-born-deep-earth-mantle |publisher=Science News|accessdate=25 December 2018}}
Blue diamonds in popular culture
Aside from the fabled curse of the Hope Diamond, blue diamonds do not yet represent a large part of world culture. However, as of 2015, blue diamonds have become the most sought-after gems at auction. This was instigated by the sale of the 9.75-carat fancy vivid blue "Zoe" diamond to Hong Kong billionaire Joseph Lau, who bought it for, and named it after, his young daughter, Zoe.{{Cite web | title = Upcoming Geneva Auctions to Reveal Three More Very Unique Diamonds |date = 11 April 2016 |url = http://www.investments.diamonds/upcoming-geneva-auctions-to-reveal-three-more-very-unique-blue-diamonds |publisher=Diamond Investment & Intelligence Center |access-date = 25 December 2016}}
An anthropomorphic character known as Blue Diamond is a member of the Great Diamond Authority in the TV show Steven Universe.
Notable blue diamonds
| class="wikitable" |
| Blue diamond
!Origin !Notability |
|---|
| Hope Diamond
| Kollur Mine, Golconda, India | One of the most famous jewels in the world, with ownership records dating back almost four centuries |
| Baby Hope Diamond
| Kalimantan, Indonesia | Once thought to be a lost piece of the Hope diamond as it phosphoresces red like the Hope. The 7.26 carat deep blue diamond originates from Kalimantan, Indonesia one of the oldest known sources of diamonds |
| Wittelsbach-Graff Diamond
| Kollur Mine, Golconda, India | Passed through Austrian royalty until it was sold at auction in 2008 to Laurence Graff and then re-polished |
| The Tereschenko Diamond
| probably Kollur Mine, Golconda, India | Originally owned by the prominent Tereschenko family, sold at auction in 1984 to Robert Mouawad |
| Heart of Eternity
| South Africa | Part of the “De Beers Millennium Jewels” display in 2000, member of the Smithsonian “Splendor of Diamonds” exhibit in Washington D.C. in 2005 |
| Sultan of Morocco Diamond
| Kollur Mine, Golconda, India | Originally owned by the Yousupov family in Russia, eventually passed to the Sultans in Morocco |
| The Transvaal Blue Diamond
|Premier Mine (now called the Cullinan Mine), Transvaal, South Africa | Once owned by the Baumgold Bros, current owner is unknown |
| The Zoe Diamond
| Probably South Africa | Originally owned by Rachel “Bunny” Mellon, was sold at auction in 2014 for $32.5 million which made it, at the time, the highest price ever paid for any diamond, the highest price ever paid for a blue diamond at auction, and the highest price per carat ever paid for a diamond.{{Cite web | title = Bunny Mellon's Blue Diamond Sells For More Than $32.6 Million, Sets Two World Auction Records| url = https://www.forbes.com/sites/anthonydemarco/2014/11/21/9-75-carat-blue-diamond-sets-two-world-auction-records/#2ac4d8ba3bf5 |website = Forbes| accessdate = 25 December 2016}} |
| The Blue Moon of Josephine Diamond
|South Africa | Sold at auction to Hong Kong billionaire Joseph Lau Luen-hung in November 2015 for his 7-year-old daughter Josephine, one year after he bought the Zoe diamond for his 12-year-old daughter Zoe. At $48.5 million, it became, at the time, the highest price ever paid for any diamond, the highest price ever paid for a blue diamond at auction, and the highest price per carat ever paid for a diamond.{{Cite web | title = Billionaire Buys 7-year-old Daughter Blue Moon Diamond for Record $48m|url = https://www.theguardian.com/world/2015/nov/12/billionaire-buys-7-year-old-daughter-blue-moon-diamond-for-record-48m |website = The Guardian |date = 12 November 2015 |accessdate = 25 December 2016}} |
| The Oppenheimer Blue Diamond
|Premier Mine, South Africa |Originally owned by the Oppenheimer family, the diamond was sold at auction in 2016 for $58 million, making it the highest price ever paid for any diamond, and the highest price ever paid for a blue diamond at auction.{{Cite web | title = The Oppenheimer Blue Diamond Helps Christie's Gain Edge|url = http://www.investments.diamonds/oppenheimer-blue-diamond-helps-christies-gain-edge/| website = Diamond Investment & Intelligence Center |date = 22 May 2016| accessdate = 25 December 2016}} |
| The Okavango Blue
|Orapa mine, Botswana |The largest blue diamond ever discovered in Botswana,{{Cite news|url=https://www.reuters.com/article/botswana-diamonds-idINKCN1RT1EY|title=Botswana shows off country's largest-ever blue diamond|date=2019-04-17|work=Reuters|access-date=2019-04-19|language=en}} it caught media attention because its original size, 41.11 carats, was comparable to that of the famous Hope Diamond, whose clarity and purity this newly discovered diamond exceeded. Its weight reduced to 20.46 carats after cutting and polishing{{Cite news|url=https://www.cbsnews.com/news/fancy-deep-blue-diamond-bostwana-rare-20-carat-blue-diamond-just-unveiled/|title=Rare 20-carat blue diamond just unveiled and it is higher in clarity than the Hope Diamond|last=Lewis|first=Sophie|date=April 17, 2019|work=CBS News|access-date=2019-04-19}} |
Gallery
File:Hope Diamond.jpg|The Hope Diamond
File:HopeDiamondwithoutLighting.JPG|The Hope Diamond without lighting
File:Fancy Blue Diamond created by Syntechno LTD.jpg|Synthetic blue diamond bracelet
See also
{{Portal|Minerals}}
References
{{reflist|35em}}
Further reading
- Cooper, J. C. (ed.) (1992). Brewer's Myth and Legend. New York: Cassell Publishers Ltd. {{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}}.
- Rachminov, Eden (2009). “The Fancy Color Diamond Book: Facts and Secrets of Trading in Rarities” New York: Diamond Odyssey. {{ISBN|9659149905}}
- Tavernier, Jean-Baptiste (1925 [1676]). [http://www.farlang.com/diamonds/tavernier-travels-india-2/page_001 Travels in India] {{Webarchive|url=https://web.archive.org/web/20140820090528/http://www.farlang.com/diamonds/tavernier-travels-india-2/page_001 |date=2014-08-20 }} (second edition), Volume II. Edited by William Crooke and translated by V. Ball. London: Oxford University Press.
- Weinstein, Michael (1958). The World of Jewel Stones. New York: Sheriden House. {{oclc|519758}}.
- Wise, Richard W. (2003). Secrets of the Gem Trade: The Connoisseur's Guide to Precious Gemstones. Lenox, Mass.: Brunswick House Press. {{ISBN|9780972822398}}. {{oclc|55662640}}. [http://www.rwwise.com/tec2.html Online Emerald chapters].