Diamonds 101

Whoever coined the phrase "diamonds are a girl's best friend" was right on the money.

These gems remain one of the most desirable gifts. Diamond sales are expected to go up this holiday season.

With that in mind, Lynn Ramsey, president of the Jewelry Information Center, gives The Early Show a refresher course in diamonds.

Cut

A quality cut is what unlocks the diamond's firey sparkle, she says. It is how a diamond is faceted to allow the maximum amount of light to be reflected through the gem.

With the right gemological tool, it is possible to see the effects of a good cut vs. a bad cut. The shallow and deep-cut glass allow light to bleed, while the ideal cut reflects light back, creating a sparkle.

A diamond's cut is not to be confused with its shape, she notes.

Color

This is the most subjective quality. Some experts consider the ideal color to be colorless; however, most diamonds display barely perceptible tints of color.

Color is graded on a scale from D (colorless or white) to Z. The best way to evaluate color is against a white surface in natural light. D, E and F colors are the most rare and therefore the most expensive, Ramsey says.

Carat

Carat refers to the weight and therefore size of the diamond. One carat weighs 0.23 grams and is divided into 100 points; therefore, a diamond weighing 50 points is a half a carat.

Clarity

Clarity is determined by how free a diamond is from inclusions, or carbon spots. Inclusions are nature's birthmarks formed in the creation process millions of years ago. Every diamond has them except for the very rarest.

Many inclusions can not be seen by the naked eye and must be viewed through a loupe or microscope, Ramsey explains.

Enhancements: While most people prefer natural untreated diamonds, clarity can be improved through enhancement technology with laser drilling or filling.

While most colored gemstones are traditionally enhanced to improve their beauty or durability, probably less than 2 percent of all diamonds are treated. And not all diamonds can be enhanced; it depends on the diamond type and the location of the inclusions, she notes.

Lasering: Laser drilling can remove or minimize the visibility of inclusions.

A laser is used to create a microscopic tunnel from the diamond surface to the inclusion, where it can be treated. Although the original inclusions are still present, the treatment improves the appearance.

Filling: Fractures, feathers, cracks or tiny surface-reaching breaks that would normally detract from a diamond's beauty can often be infused with a nearly colorless glasslike substance.

This filling has the same refrctive index as a diamond, making the fracture virtually invisible except with magnification.

This is not permanent, and special precautions are required during cleaning and repairing.

Furthermore, the Federal Trade Commission requires disclosure of enhancements. Consumers should make sure their filled diamond comes with a lifetime guarantee and that the enhancement is described on their receipt, explains Ramsey.

The cost of filled diamonds is typically 30 percent less than an equivalent nonenhanced jewel.

Whitening: In April, General Electric announced that it had discovered a process that could lighten a very limited number of diamonds without reducing their all-natural content. This new enhancement is likely to be marketed in 2000.

Moissanite: Synthetic moissanite is the newest diamond stimulant. Available since 1998, this man-made material shares many of the diamond's visual characteristics when inspected by the unaided eye.

Under 10-power magnification, however, synthetic moissanite is doubly refractive, Ramsey says.

It is sold in about 150 retail stores nationwide; the prices average about 5 percent to 10 percent of the cost of a comparable diamond.

The chemical composition of synthetic moissanite is silicon carbide while diamonds are pure carbon.

Branding: Some jewelers are laser inscribing diamonds to distinguish themselves and offer added security.

Lazare Kaplan, a major diamond manufacturer, laser inscribes diamonds with the company's initials and a six-digit code. For the millennium, the company has a limited edition line of diamonds with the 2000 date in its code, aimed at couples marrying next year.

De Beers has also launched its limited edition millennium diamond with a microscopic and tranparent inscription of a number, the De Beers mark, the millennium logo and the name of the universe's brightest stars.

When purchasing a diamond, get a recommendation for a jeweler, just as you would with a doctor, or look for one affiliated with a trade association, such as Jewelers of America.

The Jewelry Information Center Web site offers a list of members - by ZIP code and state.

Also, get everything in writing. If you're shopping online, look for a reasonable, no-questions-asked return policy with a full refund, and use a credit card.

Ramsey suggests not being bedazzled by discounts. If a retailer offers unbelievable discounts, don't believe it. Shop around.

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