The Diamond is the birthstone of April and the anniversary gemstone for the 10th and 60th years of marriage. Since diamonds are composed of a single element, they are the purest of all gemstones. Diamonds were discovered in India in 500 B.C., and the name “diamond” comes from the Greek word “Adamas” which means unconquerable – suggesting the eternity of love.
Since ancient Greece, diamonds and diamond jewelry have been the traditional symbol of love, and the ancients believed they were hardened dew drops, splinters from the stars or crystallized lightning. Today, the gem-grade diamonds are used to make fine jewelry and engagement rings. The industrial-grade diamonds are used mainly for cutting and polishing. A diamond is the hardest substance known to humankind, and is made of a crystallized carbon that has unique powers of light reflection.
THE STRUCTURE OF A DIAMOND
Proportion refers to the angles and relative measurements of a polished diamond. More than any other feature, proportions determine a diamond’s optical properties. Studies have shown that table size, crown angle, and pavilion depth have a dramatic effect on a diamond’s appearance.
Symmetry is a grading term for the exactness of shape and placement of facets. Variations in symmetry include off-center culets and tables, poor facet alignment, misshapen facets, out-of-round girdles, and wavy girdles.
ABOUT THE FOUR C’s
Because diamonds are so valuable, it’s essential to have a universal grading system for comparing their quality. In the 1940s and ’50s, the Gemological Institute of America developed the 4Cs and the GIA International Diamond Grading System™ to objectively compare and evaluate diamonds.
Diamonds and other gemstones are weighed in metric carats: one carat is equal to 0.2 grams, about the same weight as a paperclip. (Don’t confuse carat with karat, as in “18K gold,” which refers to gold purity.)
Just as a dollar is divided into 100 pennies, a carat is divided into 100 points. For example, a 50-point diamond weighs 0.50 carats. But two diamonds of equal weight can have very different values depending on the other members of the Four C’s: clarity, color and cut. The majority of diamonds used in fine jewelry weigh one carat or less.
Because even a fraction of a carat can make a considerable difference in cost, precision is crucial. In the diamond industry, weight is often measured to the hundred thousandths of a carat, and rounded to a hundredth of a carat. Diamond weights greater than one carat are expressed in carats and decimals. (For instance, a 1.08 ct. stone would be described as “one point oh eight carats,” or “one oh eight.”)
How did the carat system start?
The carat, the standard unit of weight for diamonds and other gemstones, takes its name from the carob seed. Because these small seeds had a fairly uniform weight, early gem traders used them as counterweights in their balance scales. The modern metric carat, equal to 0.2 grams, was adopted by the United States in 1913 and other countries soon after. Today, a carat weighs exactly the same in every corner of the world.
The Cut is the factor that determines the brilliance of a diamond. A classic round brilliant cut diamond has 58 facets : 33 on the top, 24 on the bottom, and the culet (1 point at the bottom). Each of the diamond’s facets must be placed in exact geometric relation to one another when the stone is being cut. Quality diamonds must be properly cut and not “spread”, which means that the proper proportions are compromised to make the diamond weigh more.
The Clarity of a diamond is based on the number, location, size, and type of inclusions found in the stone. An inclusion is an imperfection or trace mineral in the stone that is visible under the magnification of a jeweler’s loupe. The fewer inclusions the diamond has; the clearer, more brilliant and more expensive the diamond will be. A “Flawless” diamond is one that has no inclusions and is extremely rare and valuable.
Colorless and near-colorless diamonds are the most valuable. Though most diamonds may appear colorless to the naked eye, the majority of diamonds contain slight traces of yellow or light brown when viewed under a jeweler’s loupe. Depending on the stone’s size, a single increase in color grade can boost the value of a diamond by thousands of dollars per carat. A traditional engagement diamond is usually colorless or near-colorless.
In nature, diamonds can also occur in shades of red, pink, blue, green and deep yellow – These are called “Fancy diamonds”. In the United States and around the world colorless diamonds are graded on an alphabetical scale, introduced by the Gemological Institute of America (GIA). “Colorless” or “rare white” diamonds are of color grades D, E and F. Diamonds of color grade D are very rare, and extremely valuable
The weight of a diamond is measured in carats (ct.). Each carat is divided into 100 points. For example: 1ct.= 100 points, 1/2 ct. = 50 points, etc. The carat weight alone is almost meaningless unless you also consider the cut, clarity and color of the diamond. A large diamond is not very valuable if it lacks brilliance, purity and high-grade color.
However, since larger stones are rarer than smaller ones, diamond value rises exponentially with carat weight. Therefore, a diamond weighing 3.0 carats, will always be worth more than three 1.0 carat stones of the same quality. No two diamonds are exactly alike, and you must weigh all of the factors – color, cut, clarity and carat weight – when making your diamond jewelry buying decision.