Diamonds: The Most Precious of Gems

Diamonds are among the most prized substances on earth. Their incomparable brilliance, elegance, durability and mystery have captivated our imagination for thousands of years. Considering the endless lore and mystique behind this regal stone, it's no wonder that it has come to symbolize the ultimate gift of love and romance.

Not only is a diamond the overwhelming choice for prospective brides and grooms selecting an engagement ring, but the gem is also the birthstone for April. And diamonds are the recommended gift for couples celebrating their 10th, 60th and 75th wedding anniversaries.

Buying a major piece of diamond jewelry such as an engagement ring or anniversary band is one of the most expensive purchases many of us will ever make. That's why it's so important to understand the elements behind the quality and cost of a stone, so you can make an informed buying decision.

When shopping for a diamond, keep in mind that the value of a stone is determined by the "4 Cs" of cut, color, clarity and carat weight.

Cut refers to the execution of the diamond's design, the skill with which it was cut, the quality of its polish, and the overall symmetry of the stone. Diamond cuts are broadly graded as Ideal, Excellent, Very Good, Fair or Poor. A well-cut diamond releases the inner brilliance of the stone and projects its maximum amount of fire and sparkle. A poorly cut diamond allows light to leak out the sides or bottom rather than reflecting back to the eye, resulting in a "dull" diamond that may even have some "dead" spots inside.

Color refers to the presence or absence of color in white diamonds. As a rule, the whiter the stone, the greater its value. Even a slight tinge of yellow or brown could have a negative impact on a stone's value. Most diamonds are graded on the GIA color scale that begins with "D" for colorless and continues all the way down to "Z", with the color becoming more visible as you move down the alphabet. Stones in the D-F color ranges are considered the most valuable because they are the rarest.

Clarity refers to the presence of surface or internal flaws within a diamond caused during its formation. External marks are known as blemishes, while internal ones are called inclusions. Diamonds are graded for clarity on a scale ranging from "F" for flawless (no blemishes or inclusions visible under 10x magnification) to "I" for imperfect (inclusions visible to the naked eye), with numerous grades and subgrades in between. The best diamonds, of course, are flawless, but these stones are exceptionally rare and therefore very costly.

Carat weight refers to the size of the stone. The carat is the measure of weight for diamonds. One carat is approximately 200 milligrams, or 100 "points". A stone weighing a half-carat would be a 50 pointer, and so on. In general, larger diamonds are rarer and have a higher value per carat. However, other factors such as cut, color and clarity come into play as well in determining a stone's value. It's entirely possible for a smaller stone of exceptional cut, color and clarity to be worth more than a larger stone of only average quality in these areas.

There are even fancy natural colored diamonds in reds, pinks, blues, greens, yellows, browns and other colors. They vary in color richness or saturation from "faint" to "vivid", with the latter grade reserved for stones with the most vivid and deepest saturation. The value of a fancy stone depends largely on the rarity of its color (for instance, reds and greens are rarer than yellows and browns); the saturation of the color; and the purity of the color (whether the color is bright and clear or clouded by tinges of other underlying colors). Top grade fancy diamonds are extremely rare and can command tremendous prices. Probably the most famous colored diamond is the Hope, a 45.52-carat deep blue gem that resides in the Smithsonian Institution in Washington, D.C.

Even though diamonds are the hardest known substance on earth, rating a "10" on the Mohs scale of hardness, they can still be damaged if they aren't handled with care. Since only diamonds can scratch other diamonds, it's important to wrap and store your diamond jewelry pieces separately so they aren't touching one another. Also, diamond jewelry should never be worn during heavy work, since points are vulnerable to chipping and the setting can be loosened. Visit a jewelry retailer every six months to have your diamonds, mountings and settings checked.

As for cleaning, it's always best to have this done by a professional. To clean jewelry at home, you can soak your diamonds in warm, sudsy water made with any mild liquid detergent, brush with a soft toothbrush, then rinse and pat dry with a soft, lint-free cloth. Other effective cleaning methods include soaking diamonds in household ammonia, brand-name liquid jewelry cleaners and even a glass of vodka.