Colored Diamonds

Below is an article about some of the world’s most famous colored diamonds.

Diamonds are found in nature in a variety of hues. The colorless or white diamond are the most common, while some tinted stones, colored diamonds, are extremely rare and valuable. The shades of colored diamonds include yellow, blue, pink, red, green and brown.

Definition of Diamond Color – Difference between Colorless & Colored Diamonds
What is the Definition of Diamond Color and what is the difference between Colorless & Colored Diamonds? Colored diamonds contain impurities or structural defects that cause the coloration, while pure or nearly pure diamonds are transparent and colorless. Most diamond impurities replace a carbon atom in the crystal lattice. The most common impurity, nitrogen, causes a slight to intense yellow coloration depending upon the type and concentration of nitrogen present. Diamonds with a detectable hue other than yellow or brown are known as colored diamonds.
Famous Colored Diamonds
Famous Colored Diamonds are found in colors such as pink, green, red, orange, black and blue. Some of the world’s most famous diamonds are the colored ones, the heavy Dresden Green, for instance, and the infamous Hope Diamond. The Hope Diamond, which is blue in color, is thought to hold certain negative energy, and many unexplained deaths have been associated with its owners. The most famous diamonds in the world are almost always substantial in weight. There are, however, a significant number of famous diamonds that are not only large but are also colored. Many of the different colored diamonds are detailed below and the facts and information about each of the colored diamonds include an example of a famous diamond of each specific color.
The article goes on to talk about the nature of colored diamonds.

Blue Colored Diamonds
Natural blue diamonds contain the element boron (B) which changes the conductivity of the diamonds. The most famous blue diamond is the infamous Hope Diamond. The French Blue Diamond, which later became the Hope Diamond, was stolen in 1762 from the French Crown Jewels during the French Revolution.

Red Colored Diamonds
Crystal lattice defects during the formation of diamond causes the red color. Only a very few red diamonds have ever been found. Red colored diamonds are therefore extremely rare and valuable. One of the most famous red colored diamonds is the Halphen Red ( or Hancock Red). Its deep ruby color is unmatched. It was purchased in Paris by a diamond dealer called Edwin Streeter in the 19th century and famously sold at Christie’s in 1987 setting a new world per carat price for any gem.

Yellow Colored Diamonds
Natural yellow diamonds contain the element nitrogen (N). One of the most famous yellow colored diamonds is the Allnatt Diamond which is a vivid yellow color. The Allnatt Fancy Vivid Yellow 101.29 carat Diamond was found in 1950 at the Premier Diamond Mine in South Africa. It was named after its original owner, Alfred Ernest Allnatt.

Pink Colored Diamonds
Crystal lattice defects during the formation of diamond cause the pink color. One of the most famous pink colored diamonds is the Pink Agra Diamond which was acquired by the first Mogul emperor, Babur (1483-1530) in 1526.

Green Colored Diamonds
Exposure to the natural radiation in the earth such as uranium ore cause the green color. One of the most famous green colored diamonds is the Dresden Green diamond which was initially was sold to King Frederic August I in 1726 by Marcus Moses who acquired the stone in India. It has a fancy green color, weighs almost 41 carats, has 58 facets and has a pear shaped cut.

What Causes the Colors in Diamond
Every diamond has a crystal structure which is a unique arrangement of atoms in a crystal. Any defects or irregularities in the ideal atom arrangements produce an unusual crystal. The range of different colors in diamonds are due to crystal defects, the conditions that apply (such as heat and pressure) and the elements that are present when the diamond crystal is formed.
The Blue Colored Diamond is caused by the presence of the element Boron (B) which changes the conductivity of the diamonds. Red, Pink & Brown Colored Diamonds are caused by crystal lattice defects during the formation of the diamond. The Yellow Colored Diamond is caused by the presence of the element Nitrogen (N) which changes the conductivity of the diamonds. The Green Colored Diamond is caused by exposure to the natural radiation in the earth such as uranium ore.
As published on:
http://www.diamonds-are-forever.org.uk/colored-diamonds.htm

© 2011 Rare Colored Diamonds.
www.rarecoloreddiamonds.com

Colored Diamonds
posted by Rare Colored Diamonds on Wednesday, January 30, 2008

Colored Diamonds

Colored Diamonds, Gemstones and Pearls

While most diamonds are in the colorless to light yellow range, some have a natural color that is deep, distinct, and opulent. These are known as fancy-color diamonds and are often blue, brown, or pink. Unlike colorless and near-colorless diamonds which are valued for their lack of color, fancies are valued for the intensity of their color. Colored diamonds are a small but increasingly popular segment of the diamond market.

The physical conditions necessary to color a diamond naturally occur very seldom, making natural color diamonds extremely rare. For every natural color diamond, there are 10,000 colorless ones that have made the trip from the earth’s depths to its surface. It is this entirely natural process of geographical formation which ensures that each natural color diamond is one of a kind.

The formation of natural color diamonds is a process that requires the presence of additional trace elements and distortions to the typical diamond crystal. During the creation of a diamond, if an element interacts with its carbon atoms, the color can change. Natural radiation and pressure on a diamond’s structure can also intensify its color.

Rather than emphasizing the brilliance and fire coveted in near-colorless diamonds, these stones are all about the color intensity. The Argyle mine in Western Australia launched a massive marketing campaign some time ago that helped change the public’s perception of these previously overlooked diamonds. The 1987 sale of the Hancock Red, at a record auction price of $926,000 per carat, further magnified the allure of fancies.

Color Grading of Fancy Diamonds

GIA’s system for color-grading colored diamonds was developed in the mid-1950s and revamped in the mid-1990s. The diamond color grading system expresses color using the attributes of hue (the characteristic color), tone (the color’s relative lightness or darkness), and saturation (the strength or weakness of the color). Using controlled viewing conditions and color comparators, the grader determines the stone’s color from one of 27 hues. The fancy grade describes the stone’s tone and saturation with romantic names like “Fancy Light,” “Fancy Intense,” and “Fancy Vivid.”

Today, the GIA color grading system for colored diamonds is used worldwide. Many of the most famous colored diamonds, including the Blue Hope, the Dresden Green, and the Hancock Red, have been examined by the GIA laboratory using GIA’s color grading system.

GIA offers two types of diamond grading reports for colored diamonds. The GIA Colored Diamond Grading Report contains the same comprehensive diamond information as the GIA Diamond Grading Report. In addition, the GIA Colored Diamond Identification and Origin Report, known as the color-only report, gives a color grade and the nature of the color.

For complete article:
http://gia4cs.gia.edu/cm/grading-reports/colored-diamonds.htm

© 2011 Rare Colored Diamonds.
www.rarecoloreddiamonds.com

Colored Diamonds
posted by Rare Colored Diamonds on Sunday, November 25, 2007