Hearing the word jewelry immediately gives me the image of Marilyn Monroe singing in her breathless voice. Whether you're buying an engagement ring or looking for a special gift for your love, diamonds are a lovely choice.

The saying "Diamonds are forever," is true, and you want your gift to be high quality, one that your beloved will be happy to wear day in and day out. When you are making your choice, keep the four Cs in mind - carat, clarity, color and cut are the factors that affect the diamond's cost and quality.

Carat is what most of us think of when we think of a diamond's quality. And, it's probably the least understood of the four factors. The number of carats is thought by many people to be a measure of the diamond's size. In reality though, the carats tell us how much a diamond weighs. A one carat diamond weighs .20 grams, and each carat is divided into 100 points. So, a 50 point diamond weighs one-half a carat.

We might think of a one-carat diamond as the very best, but the other Cs play an important part, too. A diamond of one-half carat might have greater value than a stone of one carat, depending on the clarity, color or cut.

Clarity is something you might not have heard about until you began diamond shopping. Most diamonds contain tiny natural birthmarks, or inclusions. These birthmarks aren't usually visible when you're looking at the stone -- the jeweler has to use magnification to see them. However, inclusions can prevent light from dispersing through the diamond, and therefore affect the diamond's brilliance, even to the naked eye. Less expensive stones will usually have more and larger inclusions.

Color is the next C. You might be surprised to learn that diamonds have color, although most of the stones range from nearly colorless to a very light brown, and some even have a pink or blue-green tint. Color prevents some of the light passing through the stone, so the more color the stone has, the less shiny it will be.

A diamond's ability to shine and shimmer is affected by the color. Thus, colorless diamonds are the most brilliant, because they allow the most light to shine through the stone. Those colorless diamonds are the most expensive because they are both brilliant and rare.

Cut is the final C. Diamonds are cut to allow the maximum amount of light to be reflected back. Brilliance, fire and sparkle are what we look for in a diamond, determining how well the diamond reflects the light and shimmers. Facets are the diamond's flat panes, and the grinding and polishing of these facets is done to enhance the stone's brilliance.

When you are choosing jewelry, remember to consider all four of the Cs. Together, they combine to create diamonds that are sparklingly beautiful, truly a girl's best friend.