advt 120x600

advt 120x600

DIAMOND color is one of the 4 characteristics to be considered when evaluating a diamond. A pure diamond crystal made up of flawless structure of carbon atoms is color less and transparent. However, a variety of chemical impurities and structural imperfections impart color to diamond. Infact, no diamond is perfect in all respects. An object has color when it absorbs some colors of the white light and reflects the other colors. When white light enters a diamond crystal, impurities absorb some colors of the white light and reflect back the remaining colors to our eyes. The reflected back colors can be seen by our eyes. Color results into translucency. Color less diamonds are sometimes called white diamonds. In our discussion, we will interchangeably use the worlds "colorless diamonds" as well as "white diamonds".

In general, the more the color of a diamond, the less is its price, though this formula may reverse in the case of fancy colored diamonds. E.g: Pink and blue diamonds have high price.

The diamond crystal has an exceptionally rigid lattice. Hence it can be contaminated considerably with atoms of nitrogen and boron only during its formation. Impurities replace carbon atom in crystal lattice. This is called carbon flaw. Other elements may also replace carbon atoms in the lattice, but to an insignificant level. Whereas nitrogen imparts yellow and brown color to diamonds, boron provides gray blue colors. Some scientists are of opinion that iron oxides may also be responsible to impart yellow or brown color to diamond.

In addition to chemical contamination and structural defects, color can be introduced to diamonds artificially by irradiation. This is the cause of color in green diamonds. Structural deformations are considered as the reason of color in brown, pink and red diamond stones.

The faint yellow or brown color of a diamond is mostly unnoticeable by a common buyer, but it does affect price of the diamond. Actual color of a diamond is noted when it is compared with a perfectly white diamond. A diamond color grader should have perfect color distinguishing ability. He should not be a color blind. Diamond color should be noted when there is sufficient white light available. Evening light or colored light is not suitable for judging the color of a diamond.

A diamond stone can disperse white light into its component seven colors. This results into dazzling luster. The ability to disperse light is called as optical dispersion. Diamond refracts different colors of white light into different angles. Hence it splits the colors.

Color of diamond can be seen with face up and face down. Refraction and dispersion of light may confuse or disguise the original color of diamond. According to GIA guidelines, color of a diamond should be graded unmounted and viewed face down in natural day light or natural day light simulation. A mounted diamond can not be judged properly for its color, the reason is that the mounting metal's color will reflect into the color of diamond. Shape and size of diamond also affect the color appearance of a diamond and people often make mistake to judge the exact color.

Mostly people wish to buy a diamond as white (color less) as possible for its purity. Commonly found diamonds are yellow, gray or brown to white.

GIA has provided a scale to grade the color of a diamond ranging from D (white) to Z (yellow).

D, E, F are white diamonds. They are rarest diamonds and most precious of all colors. The only difference among D, E, F is of transparency. D is the most transparent and absolutely white. D color diamonds have a unique icy look. D color diamond set is called white diamond set. A white diamond set has unmatched beauty. D color diamonds are rarest of the rare diamonds. E color is less transparent than D. E color diamonds have minor traces of color, which can be noticed with difficulty by an expert gemologist under microscope. E color diamonds are also very rare. F is the least transparent of all the 3 colors. Insignificant color can be seen by an expert gemologist. F color diamonds are also considered as white diamonds. Like D and E colors, the F color diamonds are also very high quality diamonds. The difference in transparency of D, E, F color diamonds is noticeable by an expert under microscope only.

G, H, I, J diamonds are called near colorless (or near white) diamonds. They appear near white when seen from face up, but slight color is seen when viewed from face down and white background. Color is visible only when these diamonds are compared with diamonds of better color grade. For example: If D color diamond is compared with J color diamond under magnification and controlled light conditions, small difference in color is visible. However, no color is noticeable practically in the diamonds of this category. A common man can't tell the difference in D and G diamonds even when they are kept side by side. Diamonds of G, H, I, J colors offer excellent value of money you spend to buy them. They cost you less than D, E, F color diamonds and still look too good. Most of the people and wise salespersons will recommend you to buy diamonds of G, H, I, J colors. Once mounted, you won't be able to see any color in well cut diamonds of G, H, I, J category, because they are mounted face up. And they look white when seen from face up. The larger the size of diamond, the easier it is to detect the color. Usually we don't buy diamonds that have more than 1.5 carat weight. Upto this much weight, it is unlikely to notice the a faint color. I recently asked a jeweller to guess the color of a solitaire diamond ring of 1.35 carat weight with unaided eye. He was only able to say the world "colorless". The ring in question was " H " color as mentioned in its GIA certificate. Most of the world's jewelry like ring, bracelet, pendant and set etc are made from diamonds of this color grade.

K, L, M have faint yellow color visible to naked eye when seen carefully. Diamonds of K, L, M color grades are not advisable for fine jewelry. Big brands never use diamonds of this color grade or lower grades.

N O P Q R have very light yellow color. Color can be seen easily with naked eye. Diamonds of these colors are not attractive at all and should not be used to make jewelry.

S T U V W X Y Z have light yellow color. Tint more visible. Sometimes brownish tint is also visible in these diamonds. These are the inferior color diamonds.

Diamonds with color between D to Z are called normal color diamonds. After Z, there is a Z+ category. The diamonds that fall in Z+ category are called exotic or fancy color diamonds. These diamonds have colors like deep yellow, deep blue, violet, orange, pink, red, purple, green, black violet and translucent white. Diamonds with colors other than yellow and brown are very rare. Red diamonds are very very rare. Colorimeter is a computer based instrument that accurately grades the diamond.

Black diamonds are also called Carbonado. These are inferior quality diamonds. They appear to be black in color because of presence of a large number of dark impurities. Carbonados are used in cutting, drilling and polishing industry. They are more porous than any other diamond. They are found in Central African Republic and Brazil.

Why are colorless (white) diamonds preferred?

People prefer to buy white diamonds instead of yellowish or brownish diamonds. Let us try to understand the scientific reason behind this. White color diamonds are more beautiful than yellow or brown. When white light enters into a diamond, it is dispersed to form a spectrum of seven colors. In other words, diamond acts as a prism to split white light into seven colors. A diamond which produces a good spectrum is said to have good "fire". Color in a diamond acts as filter for white light and tends to reduce the quality of the spectrum formed. In other words, white diamonds form better spectrum than colored diamonds. Hence the less color a diamond has, the better the fire it has, the better the color grade it has.

Diamond Color Treatment

High pressure and high pressure treatment can change the color of diamonds. Color of a diamond can also be changed by irradiation treatment followed by heat treatment. Mounting a diamond in a metal of particular color also affects its color appearance. For example, a J color diamond mounted in a white gold or platinum jewel will cause its color to appear perfectly white.

Suggestion: If you are looking for cheap price diamonds, don't hesitate to buy diamonds upto J color. Infact, G, H, I, J color diamonds appear to be as good as D, E. F color diamonds with naked eye. Buying a perfectly color less diamond of D, E or F grade is just wastage of money for budget conscious people. Perfectly color less diamonds are bought by the class of people who are social status conscious and money does not matter to them.

How can an average man distinguish colors of diamonds?

Spend plenty of time in looking at certified diamonds of various color grades and your analytic mind will soon start making fine distinction among various color grades. Get guidance from an experienced gemologist about right lighting environment. Color sensitivity develops with practice. Keep one thing in mind, a well cut diamond gives illusion of a better color grade. Beware of lighting environment of most of the jewelry showrooms. They have lighting environment to make diamonds look whiter in color.