Blue diamonds are the rarest of the rare, and their beauty has been sought after for centuries. The best known blue diamond in the world is the legendary Hope diamond, which is famous for its deep blue color and large size, and notorious for the curse rumored to fall upon anyone brave enough to wear it.
The value of a diamond is determined by four factors, usually referred to as "the 4 C's"; carat, cut, clarity, and color:
*Carat refers to the mass of the diamond, with larger stones tending to be more valuable than smaller stones as long as the other factors are equivalent.
*Cut refers to how the stone has been shaped and polished. This actually refers to the quality of workmanship and the angles to which the stone has been cut, rather than to the stone's shape as most laymen believe.
*Clarity measures the imperfections (called inclusions) in the stone, with stones having fewer imperfections being more valuable. Inclusions may be structural imperfections like tiny cracks in the diamond or crystals of another material, or even other diamond crystals.
*Color is perhaps the most important measure of a diamond's value. A "perfect" diamond is completely transparent, with no hint of color; however, this is extremely rare. The color of a diamond is affected by chemical impurities and defects in the structure of the crystal, and is judged by four specific criteria; distribution, saturation, tone, and hue.
*Distribution refers to how even the color is throughout the body of the stone.
*Saturation is the intensity of the color present, with more saturated (darker) stones being more valuable.
*Tone describes how light or dark a stone appears, and depends on the amount of black, brown, gray, or white is present.
*Hue refers to the actual color of the diamond, and can be any color of the spectrum. Many stones have one dominant hue, and one or more underlying colors.
Diamonds were formed by carbon atoms subjected to extreme pressure and heat in the crust of the earth. If some of the carbon atoms are replaced by boron, the diamond has a blue color, which can range from the faintest trace of blue to the rich, deep blue of the Hope Diamond. Diamonds containing boron are semi-conductive, with unique electrical properties not found in stones of other colors. Hydrogen in high concentrations in a diamond can cause a blue-gray color, but these stones are not semi-conducting.
Blue diamonds are among the most desired by collectors, and can sell for millions of dollars. According to Diamond Source of Virginia, a 20.17 carat blue diamond sold for $9 million at Sothesby's in 1994; and a year later a 6.70 carat blue sold for $3.52 million.
Diamond Source of Virginia. (retrieved August 20, 2009.)http://www.diamondsourceva.com/Education/ColoredDiamonds/colored-diamonds-blue.asp http://www.diamondsourceva.com/Education/ColoredDiamonds/ColoredDiamonds.asp
Aber, Susan Ward. Everything You Always Wanted to Know About Diamond. (retrieved August 20, 2009.) http://www.emporia.edu/earthsci/amber/go340/diamond.htm
Diamonds Team. The Facts About Blue Diamonds. (retrieved August 20, 2009.) http://www.diamonds-team.com/a05-the-facts-about-blue-diamonds.php