Blue diamond is a type of
diamond
Diamond is a Allotropes of carbon, solid form of the element carbon with its atoms arranged in a crystal structure called diamond cubic. Another solid form of carbon known as graphite is the Chemical stability, chemically stable form of car ...
which exhibits all of the same inherent properties of the mineral except with the additional element of blue color in the stone. They are colored blue by trace amounts of
boron
Boron is a chemical element with the symbol B and atomic number 5. In its crystalline form it is a brittle, dark, lustrous metalloid; in its amorphous form it is a brown powder. As the lightest element of the ''boron group'' it has th ...
that contaminate 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 absolute most important criterion in grading a blue diamond and determining its value.
However, the most valuable of blue diamonds also exhibit the highest clarity grades. There is no known blue diamond with a completely flawless (F) clarity grading, although several are known which are graded Internally Flawless (IF).
One of the earliest mentioned blue diamonds is the
Hope Diamond
The Hope Diamond is a diamond originally extracted in the 17th century from the Kollur Mine in Guntur, India. It is blue in color due to trace amounts of boron. Its exceptional size has revealed new information about the formation of diamonds. ...
, 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
Jean-Baptiste Tavernier (1605–1689) was a 17th-century French gem merchant and traveler. Tavernier, a private individual and merchant traveling at his own expense, covered, by his own account, 60,000 leagues in making six voyages to Persia ...
, after whom it was called the
Tavernier Blue
The Tavernier Blue was the precursor diamond to the Blue Diamond of the French Crown (aka the French Blue). Subsequently, most scholars and historians believe that it was re-cut and, after a disappearance and reemergence into the public forum, w ...
. Its last owner was famed jeweler
Harry Winston
Harry Winston (March 1, 1896December 8, 1978) was an American jeweler. He donated the Hope Diamond to the Smithsonian Institution in 1958 after owning it for a decade. He also traded the Portuguese Diamond to the Smithsonian in 1963 in exchang ...
before he donated it to the
Smithsonian National Museum of Natural History
The National Museum of Natural History is a natural history museum administered by the Smithsonian Institution, located on the National Mall in Washington, D.C., United States. It has free admission and is open 364 days a year. In 2021, with 7. ...
in Washington, D.C. 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, color is divided into three components: ''
hue
In color theory, hue is one of the main properties (called Color appearance model#Color appearance parameters, color appearance parameters) of a color, defined technically in the CIECAM02 model as "the degree to which a Stimulus (physiology ...
'', ''
saturation
Saturation, saturated, unsaturation or unsaturated may refer to:
Chemistry
* Saturation, a property of organic compounds referring to carbon-carbon bonds
**Saturated and unsaturated compounds
** Degree of unsaturation
**Saturated fat or fatty aci ...
'' 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 there is no secondary color present but rather are a pure blue color. 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.
[
] Most pure blue diamonds are
Type IIb
In theoretical physics, type II string theory is a unified term that includes both type IIA strings and type IIB strings theories. Type II string theory accounts for two of the five consistent superstring theory, superstring theories in ten dimens ...
, meaning they contain either very few or a complete lack of nitrogen impurities.
Type Ia
A Type Ia supernova (read: "type one-A") is a type of supernova that occurs in binary systems (two stars orbiting one another) in which one of the stars is a white dwarf. The other star can be anything from a giant star to an even smaller white ...
blue stones contain a secondary hue and get their color from the presence of hydrogen.
Clarity
As with all diamonds, the
loupe
A loupe ( ) is a simple, small magnification device used to see small details more closely. They generally have higher magnification than a magnifying glass, and are designed to be held or worn close to the eye. A loupe does not have an attached h ...
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.
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.
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 the value or resale value of a natural blue diamond. 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
Lab-grown diamond (LGD; also called laboratory-grown, laboratory-created, man-made, artisan-created, artificial, synthetic, or cultured diamond) is diamond that is produced in a controlled technological process (in contrast to naturally formed ...
.
Blue diamond mines
The earliest recorded blue diamond, the
Hope Diamond
The Hope Diamond is a diamond originally extracted in the 17th century from the Kollur Mine in Guntur, India. It is blue in color due to trace amounts of boron. Its exceptional size has revealed new information about the formation of diamonds. ...
, was discovered in
India
India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the so ...
, in the
Kollur mine
Kollur Mine was a series of gravel-clay pits on the south bank of the Krishna River in the Golconda Sultanate of India. It currently falls within the state of Andhra Pradesh. It is thought to have produced many large diamonds, known as Golcon ...
in the
Guntur
Guntur () is a city and the administrative headquarters of Guntur district in the Indian state of Andhra Pradesh. Guntur is spread across 168.49 km square and is the third-largest city in the state. It is situated to the west of the Ba ...
district of
Andhra Pradesh
Andhra Pradesh (, abbr. AP) is a state in the south-eastern coastal region of India. It is the seventh-largest state by area covering an area of and tenth-most populous state with 49,386,799 inhabitants. It is bordered by Telangana to the ...
(which at the time was part of the
Golconda kingdom), in the seventeenth century. However, blue diamonds have also been discovered in the
Cullinan Mine Cullinan may refer to:
* Cullinan (surname), a surname
*Rolls-Royce Cullinan, an ultra-luxury SUV produced by Rolls-Royce Motor Cars
* Cullinan, Gauteng, a small town in South Africa
*Cullinan Diamond, the largest rough gem-quality diamond ever fou ...
in
South Africa
South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring countri ...
and the
Golconda
Fort (Telugu: గోల్కొండ, romanized: ''Gōlkōnḍa'') is a historic fortress and ruined city located in Hyderabad, Telangana, India. It was originally called Mankal. The fort was originally built by Kakatiya ruler Pratāparu ...
region.
A few blue diamonds have been discovered in the
Argyle Mine
Argyle is an archaic spelling of Argyll, a county in western Scotland. Argyle may refer to:
Places Australia
* Argyle, Victoria
* Argyle County, New South Wales
**Electoral district of Argyle, a former electoral district for the Legislative ...
in
Western Australia
Western Australia (commonly abbreviated as WA) is a state of Australia occupying the western percent of the land area of Australia excluding external territories. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to th ...
as well, and are offered at their annual
Argyle Tender
Argyle is an archaic spelling of Argyll, a county in western Scotland. Argyle may refer to:
Places Australia
* Argyle, Victoria
* Argyle County, New South Wales
**Electoral district of Argyle, a former electoral district for the Legislative ...
when they are found. 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
Serpentinite is a rock composed predominantly of one or more serpentine group minerals, the name originating from the similarity of the texture of the rock to that of the skin of a snake. Serpentinite has been called ''serpentine'' or ''ser ...
carried down to the mantle by subducting ocean
tectonic plate
Plate tectonics (from the la, label=Late Latin, tectonicus, from the grc, τεκτονικός, lit=pertaining to building) is the generally accepted scientific theory that considers the Earth's lithosphere to comprise a number of large te ...
s.
Blue diamonds in popular culture
Aside from the fabled curse of the
Hope Diamond
The Hope Diamond is a diamond originally extracted in the 17th century from the Kollur Mine in Guntur, India. It is blue in color due to trace amounts of boron. Its exceptional size has revealed new information about the formation of diamonds. ...
, 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.
An anthropomorphic character known as Blue Diamond is a member of the Great Diamond Authority in the TV show
Steven Universe
''Steven Universe'' is an American animated series, animated television series created by Rebecca Sugar for Cartoon Network. It tells the coming-of-age story of a young boy, Steven Universe (character), Steven Universe (Zach Callison), who li ...
.
Notable blue diamonds
Gallery
File:Hope Diamond.jpg, The Hope Diamond
File:HopeDiamondwithoutLighting.JPG, The Hope Diamond without lighting
File:Hope diamond copy.jpg, Replica of the Hope Diamond
File:SucherTavernierBlueReplicaRW.jpg, A replica of the Tavernier Blue
File:Toison2010.png, Replica of the French Blue (Tavernier Blue) in a recreation of the Order of the Golden Fleece
The Distinguished Order of the Golden Fleece ( es, Insigne Orden del Toisón de Oro, german: Orden vom Goldenen Vlies) is a Catholic order of chivalry founded in Bruges by Philip the Good, Duke of Burgundy, in 1430, to celebrate his marriage ...
of King Louis XV of France
See also
*
Red diamond
A red diamond is a diamond which displays red colour and exhibits the same mineral properties as colourless diamonds. Red diamonds are commonly known as the most expensive and the rarest diamond colour in the world, even more so than pink or bl ...
*
Pink diamond
Pink diamond is a type of diamond that has pink color. The source of their pink color is greatly debated in the gemological world but it is most commonly attributed to plastic deformation that these diamonds undergo during their formation.
Pink ...
*
List of minerals
This is a list of minerals for which there are articles on Wikipedia.
Minerals are distinguished by various chemical and physical properties. Differences in chemical composition and crystal structure distinguish the various ''species''. Within a m ...
*
List of diamonds
Diamond (gemstone), Diamonds become famous typically for some combination of their size, color and quality. Diamonds occur naturally in many different colors, so the largest diamond of a particular color may not be large in absolute terms, but it ...
References
Further reading
* Cooper, J. C. (ed.) (1992). ''Brewer's Myth and Legend''. New York: Cassell Publishers Ltd. .
* Hurlbut, Cornelius S.; Klein, Cornelis (1985). ''Manual of Mineralogy'' (20th ed.). New York: John Wiley and Sons. .
* Rachminov, Eden (2009). “The Fancy Color Diamond Book: Facts and Secrets of Trading in Rarities” New York: Diamond Odyssey.
* Tavernier, Jean-Baptiste (1925
676
__NOTOC__
Year 676 ( DCLXXVI) was a leap year starting on Tuesday (link will display the full calendar) of the Julian calendar. The denomination 676 for this year has been used since the early medieval period, when the Anno Domini calendar era ...
''Travels in India'' (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. .
* Wise, Richard W. (2003). ''Secrets of the Gem Trade: The Connoisseur's Guide to Precious Gemstones''. Lenox, Mass.: Brunswick House Press. .
External links
{{Gemstone
Diamond colors
Blue diamonds