Origin of name
The Peacock diamond gets it's name from the present
owners of the diamond, C.D. Peacock, Chicago's Premier jewelry store,
founded in 1837.
Characteristics of the
According to the Gemological Institute of America, the
diamond is a 20.65-carat, fancy intense yellow, internally flawless (IF),
radiant-cut stone with dimensions of 15.62 X 14.49 X 9.37 mm. Fancy intense
grade among yellow diamonds is not so common. The rarity of this color
combined with the size, make this stone a unique and notable diamond. In the
photograph the diamond is displayed on a special mount made up of Platinum
and 18k Gold flanked on either side by modified triangular-cut D-color
The radiant-cut is a combination of the emerald-cut and
brilliant-cut, that was developed in the 1970s. Like the emerald-cut, the
radiant-cut has trimmed corners, making the diamond eight-sided. The
emerald-cut is used on the top of the diamond, and the brilliant-cut facets
on the bottom of the diamond. The radiant-cut diamond therefore,
incorporates the properties of both cuts, the emerald-cut and the
brilliant-cut. The radiant-cut has the brilliance of the brilliant round
diamonds, and the ability to show off the color, characteristic of
Being a yellow diamond, the Peacock diamond is obviously
a type I diamond, whose distinguishing feature is the presence of trace
quantities of Nitrogen as impurities, in the crystal. Under type I diamonds
there are two sub-groups that can show off the yellow color - type IaAB and
type Ib. In both groups the ability to show off the yellow color is
associated with the distribution of Nitrogen as groups of odd numbers. In
IaAB besides groups of 2 and 4 atoms which do not affect the color of
diamonds, Nitrogen also exists as groups of 3 atoms known as N3 centers,
which absorb visible light in the blue end of the spectrum, imparting a pale
to medium yellow color to the diamonds. In type Ib diamonds Nitrogen occurs
as single atoms (1 is an odd number), and these atoms also absorb light in
the blue end of the spectrum imparting an intense yellow color like the
canary yellow color. The Peacock diamond may belong to either one of these
two groups- type IaAB or type Ib.
The House of Peacock, was first established in 1837, the
same year Chicago was incorporated as a city. This was the first retail
jewelry establishment in Chicago, and according to some historians marked
Chicago's passing "from the semi-savage conditions to civilization and
The founder of the company was Elijah Peacock, a skilled
third generation watch and jewelry repairman. In 1889, Elijah appointed his
son Charles Daniel as successor to the company and the name of the company
was changed to C. D. Peacock. As the city of Chicago grew, the company also
expanded along with it. Each store was designed to be a show place for the
finest jewelry, watches and gifts. As the oldest guild jeweler in the
Chicago area, C. D. Peacock is committed to excellence, quality and service.
The Peacock diamond was put on a special mount made up of
platinum and 18K gold, flanked on either side by two triangular-cut
colorless (white) diamonds and displayed at C. D. Peacock, Northbrook Court,
Chicago, along with other rare fancy colored diamonds, fine and antique
jewelry and unique accessories.
The whole idea of purchasing this unique fancy intense
yellow diamond , and displaying it with two triangular-cut colorless
diamonds on either side, was to educate the public about the existence of
diamonds in fancy colors other than the usual white or colorless diamonds.
The common public perception is that diamonds exist only in one color- i.e.
colorless or white. The exhibition of the Peacock diamond and other rare
fancy colored diamonds was to change this public perception, and to
enlighten the public that diamonds do exist in other colors, beside the
colorless or white variety.
Mr. Ray Perlman, former chairman of the New York Diamond
Dealers Club, and a consultant to C. D. Peacock says that most people have
no idea that diamonds occur in a color other than white ( colorless). Yet
when you ask them to name some of the world's most famous diamonds, almost
invariably they would mention the Hope Diamond, which is a fancy intense
blue diamond, and the Tiffany Diamond, which is a golden yellow diamond.
Color in diamonds
Contrary to public perception, the commonest colors in
diamonds are yellow and brown. A majority of diamonds that are mined are in
the range of pale yellow to brown color. This is known as the normal color
range. This is obvious because 98 % of all naturally occurring diamonds
contain Nitrogen atoms as impurities which can impart a yellow to brown
color when scattered as single atoms or found in groups of odd numbers such
as three atoms. Most white diamonds that occur naturally also have a tinge
of yellow in them showing the presence of Nitrogen impurities. However
absolutely colorless diamonds without any Nitrogen impurities are also
found, but are very scarce. They constitute only about 1-2 % of all
naturally occurring diamonds. D, E, and F color grades of diamonds may fall
under this category.
Blue diamonds that are formed due to the presence of
trace amounts of Boron are also scarce and constitute about 0.1 % of all
naturally occurring diamonds.
Pink, red, purple and brown diamonds are formed due to
plastic deformation of diamond crystals caused by the twisting and bending
of the tetrahedral crystal units as the diamond rose from deep down the
earth's mantle to the surface. Pink, red, and purple colors are extremely
rare in occurrence, however red and purple are the rarest. Brown color is
quite common. In the Argyle mines in Western Australia around 72 % of the
diamonds produced are brown in color caused by plastic deformation of
crystals. These diamonds are processed in India and marketed by Argyle as
Cognac and Champagne diamonds.
Green color in diamonds is caused by exposure of diamonds
to natural irradiation over a long period of time. The diamonds had absorbed
magenta wave lengths that impart the green color. Green diamonds are also
extremely rare in occurrence.
Besides the cut, clarity, shape and weight, two other
important factors that determine the price of colored diamonds are the
rarity of the color and it's intensity. Red and purple diamonds being the
rarest fetch the highest prices, followed by green and blue, which are the
next rarest in occurrence.
The 0.95-carat fancy red round brilliant diamond, the
Hancock Red set the world record price per carat for diamonds, when it was
sold in 1987, at $ 926,000 per carat. In 1997 a 13.83-carat fancy vivid
yellow diamond was sold at Sotheby's New York for a record price of $ 3.3
million. This works out to about $ 239,000 per carat. The previous record
for an intense yellow diamond set in London in 1990 was $ 202,000 per carat.