| The Gemological Institute of America (GIA), | | | | diamonds that derived their color from |
| the American Gem Society (AGS), and the | | | | impurities imbedded in the diamond, Pink |
| International Gemological Institute (IGI) are | | | | diamonds are considered a Type II and get |
| the three most widely known and respected | | | | their color from a process known as Plastic |
| diamond grading laboratories in the world. | | | | Deformation. |
| Each of the grading laboratories have | | | | |
| developed a very similar nomenclature for | | | | Type II diamonds have very few if any |
| identifying the 4 C's of diamonds. | | | | nitrogen impurities in them. They get their |
| | | | coloration due to structural anomalies caused |
| D to Z | | | | by Plastic Deformation during the crystal |
| | | | growth. The intense pressure changes the |
| Color grading scales used by the | | | | lattice structure of diamonds and has led to |
| internationally recognized laboratories (GIA | | | | the formation of Pink, and Red colored |
| & IGI for example), ranges from totally | | | | diamonds. |
| colorless (D) to pale yellow or brown color | | | | |
| (Z). Brown diamonds darker than K color are | | | | Green Diamond |
| usually described using their letter grade, | | | | |
| and a descriptive phrase, for example M Faint | | | | A natural diamond coming into contact with a |
| Brown. Diamonds with more depth of color | | | | radioactive source at some point during its |
| than Z color fall into the fancy color | | | | lifetime causes some diamonds to develop a |
| diamond range. | | | | green coloration. The time required may be |
| | | | as much as a million years or longer. Green |
| The coloration of diamonds can be caused by | | | | diamonds of this nature are very unique. |
| several factors. Impurities trapped in the | | | | |
| diamond during its formation, the crystal | | | | The most common form of irradiation diamonds |
| lattice structure of the diamond, and the | | | | comes from alpha particles found in uranium |
| exposure to radiation can all lead to the | | | | compounds or from percolating groundwater. |
| wide verity of colors available in diamonds. | | | | Green spots on the surface of the diamonds or |
| | | | a thin green film may develop on the skin of |
| Yellow Diamonds | | | | the diamond after long exposure to these |
| | | | particles. Many times this green coloration |
| Yellow diamonds are colored because of the | | | | will be removed during the cutting or |
| impurities that are trapped inside diamonds | | | | faceting process. |
| when they are created. If a few of the | | | | |
| millions of carbon atoms have been replaced | | | | Bombardment by beta and gamma rays will color |
| by nitrogen atoms, then structure of the | | | | the diamond to a greater depth and in some |
| diamond will not be significantly altered but | | | | rare case turn the entire stone green. |
| the clarity will be changed. The amount of | | | | Heating to temperature to just below 600 |
| color displayed is dependent on the amount of | | | | degrees Celsius can sometimes also cause a |
| nitrogen involved. | | | | diamond to develop a green ting. Higher |
| | | | temperature may turn the stone to a less |
| When we see color it is because the object we | | | | desirable yellow or brown color. |
| are looking at reflected a specific | | | | |
| wavelength of the light spectrum. A good | | | | Black Diamond |
| example of this is a yellow flower. The | | | | |
| flower absorbs all of the light except the | | | | Black diamonds are found only in Brazil and |
| yellow light, which is reflected by the | | | | the Central African Republic. Approximately |
| yellow flower. | | | | 600 tons of conventional diamonds have been |
| | | | mined, traded, polished since 1900. But not a |
| Blue Diamond | | | | single black diamond has been discovered in |
| | | | the world's mining fields. The geological |
| In the case of a blue colored diamond some of | | | | settings where diamonds are found or mined |
| the nitrogen has been replaced by Boron. | | | | are virtually identical with the one |
| Boron will reflect the blue wavelength of the | | | | exception, the Black Diamond. |
| light spectrum. The higher the concentration | | | | |
| of boron the more color will be showed. At a | | | | Black diamonds have been found to contain |
| level of one or a few boron atoms for every | | | | trace elements of nitrogen and hydrogen. The |
| million-carbon atom, an attractive blue color | | | | study published in 2006 analyzed the hydrogen |
| results. | | | | in black diamond samples using |
| | | | infrared-detection instruments and found that |
| Pink Diamond | | | | the quantity indicated that the mineral |
| | | | formed in a supernova explosion prior to the |
| The pink diamonds comes in shades ranging | | | | formation of the Solar System. These |
| from a pastel rose, such as the Pink Orchid | | | | diamonds were formed by carbon-rich cosmic |
| to intense purple-reds of the Moussaieff Red, | | | | dust in an environment near carbon stars. The |
| and the price is determined by the intensity | | | | diamonds were incorporated into solid bodies |
| of the color. Pink diamonds have sold for up | | | | that subsequently fell to Earth as |
| to $1,000,000 a carat. Unlike the Type I | | | | meteorites. |