Definitive : Diamonds: The Kindest Cut of All

Before the 15th Century, the diamond was reserved forroyalty, but today it’s so pervasive that even toddlers tote minute diamond stud earrings.

But by most accounts, it is the adult woman who wears the real gems.

As the most enduring of all the world’s gemstones, the diamond--a pure or nearly pure form of carbon--stands as the ultimate symbol of lasting quality.

A glittering history: Diamonds are forever, except when placed on an anvil and struck with a hammer. That was the test applied to stones during the last days of the Roman Empire to determine a fake stone from a real adamas (the word diamond is a corruption of this Greek word meaning invincible ). But even the hardest natural substance on earth could not always withstand this grueling exam, and many beautiful and rare diamond crystals were shattered.

With the early days of the Renaissance came the art of diamond cutting and polishing. Louis De Berquem of Bruges, a Flemish gem cutter, is often credited with discovering the secrets of how to cut and polish diamonds so that their true fire could be released. He recognized the importance of accurate geometrical faceting, thereby laying the foundations for the brilliant cut which maximizes the internal light reflection of a stone.

Diamonds occur naturally in crystal form with the most common shape being the octahedron, although they can be found with as many as 48 faces (hexoctahedron). The world’s most important diamond deposits are in Africa. South Africa in particular contains the largest source of gem diamonds for fine jewelry. Diamonds are also found in Brazil, Australia, India, Israel, Antwerp, Amsterdam and the United States.

Engaging ideas: Diamonds, of course, pop up in engagement rings. The one boasting the round-brilliant cut solitaire with its 58 facets has retained its popularity year after year. Five to 10 years ago the marquise was the diamond of the moment; today it’s second only to the brilliant cut.

The “star burst� or “princess� cut resembles the shape of an emerald cut but with more faceting on the bottom. This additional styling gives more fire to the classic emerald silhouette. The woman attracted to this cut is “someone who is getting married for the first time, who is exposed to the work world, interested in fashion as a style rather than a trend and is also aware of national advertising,� says Jo Ellen Qualls, vice president of Tiffany & Co., the fine-diamond purveyor that created the famous six-pronged setting that holds a diamond away from the band to add to its brilliance.

Sparkling personalities: Qualls proposes that the emerald cut draws the attention of the woman who knows exactly what she wants and makes no pretense about it. The round-brilliant cut lends itself to an individual who is traditional and conservative. The oval shape is preferred by a woman who surrounds herself with friends. The marquise typifies the energetic and outgoing woman who likes a lot of movement in her life. And the heart-shaped diamond is for the incurable romantic.

Whatever shape is selected, other decisions have to be made: Will it rest in a gold or platinum setting? In solitaire form, or with trillions or baguettes for accent? With or without other precious gemstones such as emeralds, rubies and sapphires?

Platinum casts no color onto the stone and is the most enduring of the two metals. For these reasons, it is recommended by Tiffany & Co.

With the other decisions, make them carefully, especially with an engagement or wedding ring, which should be made in a style that will endure. Some couples add an “anniversary� band or “eternity� ring for every year they’re married.

The diamond straight-line bracelet (also known as the “tennis bracelet� after Chris Evert took hers to the court) has been popular since the turn of the century.

Animal instinct: Brooches are favored by working woman as wardrobe enhancers, especially fauna shapes such as giraffes, lions, tigers and bears. The classic shapes include the leaf and floral motif.

Much like the “parure� of the 18th Century--a matching set of jewelry consisting of necklace, brooch, earrings, bracelet and tiara--the modern woman might have a working diamond wardrobe consisting of much the same, sans the tiara.

Brilliant ideas: Before you buy, get the facts.

According to the Gemological Institute of America, there are generally four criteria upon which the value of a diamond is based:

* clarity

* color

* cut

* carat weight

Clarity relates to a stone’s relative position on a flawless-to-imperfect scale. A flawless (FI) diamond shows no blemishes or inclusions when examined by a skilled grader under 10 times magnification. An internally flawless (IF) diamond shows no inclusions and only insignificant blemishes under 10 times magnification. A very very slightly included (VVS) diamond contains minute inclusions that are either extremely difficult (VVS1) or very difficult (VVS2) to locate under 10 times magnification.

A very slightly included (VS) diamond contains minor inclusions that range from difficult (VS1) to somewhat easy (VS2) to see under 10 times magnification. A slightly included (SI) stone contains noticeable inclusions which are easy (SI1) or very easy (SI2) to see under 10 times magnification. And finally, an imperfect (I) grade stone contains inclusions which are obvious under magnification, or perhaps even to the unaided eye. I1 signifies a moderate effect on the stones beauty or durability, and I2 and I3 signifies a severe effect on beauty or durability.

Utilizing an alphabetic scale, the color grade of a diamond is determined (in descending order) to be colorless (D, E, F), to near colorless (G, H, I, J), to faint yellow (K, L, M), to very light yellow (N, O, P, Q, R), to light yellow (S, T, U, V, W, X, Y, & Z), and on to fancy (Z+--off the scale).

Diamonds are not as rare as some might believe; however, the purest colorless form of diamonds are scarce and the most expensive. The unique “fancy diamonds� are a separate group from the colorless to light yellow. These desirable freaks of nature range in shades that include yellow, pink, blue, red (very rare), orange and green. Some of the most famous diamonds, such as the canary-yellow Tiffany Diamond and the blue Hope Diamond are indeed fancy.

The cut of a diamond refers to the proportions and finish of a polished diamond, but also to the shape, as in round-brilliant, marquis, cushion, oval, emerald and pear cuts. Facet shapes and placement affect the finish and optical efficiency of the stone, and therefore help to determine the value and resulting price.

The size of the stone aids in value determination. The standard unit of weight for diamonds is the metric carat, which equals 0.200 gram.

“We think size is important, but unimportant if that is the only thing that is viewed,� Qualls says. “A larger stone that is poorly cut is not worth as much as a smaller well-cut diamond.�

Proper proportions are more important to the resulting beauty and brilliance of a stone than the actual size, although many cutters will sacrifice proportion in favor of a heavier stone that might appeal to the customer in search of a big diamond.