Diamonds - The Four C's

When you see a diamond, the first thing that comes to mind is the beauty of the stone. The diamond sparkles and you can't help thinking the piece is priceless. But for the average unaided eye, it's hard to determine if the diamond is worth the asking price. Here are some characteristics of diamonds that can help you better determine the diamond's worth.

For professionals, diamonds are measured by the 4 C's: Color, Clarity, Carat and Cut. These attributes determine if the precious stone is worth more or less.

Can diamonds have color? Most diamonds would appear without color, but with close observation (or through the help of a magnifying glass), diamonds may indeed have color. Some diamonds may look like they are yellow or some may have tints of grey or brown. In most cases, if the diamond has color, it's very faint. For a diamond to be assessed well, the color must be deemed "colorless".

According to the Gemological Institute of America (GIA), diamonds are graded by the following categories (in order from highest): Colorless, Near Colorless, Faint Yellow, Light Yellow and Fancy. The diamonds are categorized even further into the color grades such as D, E and F for Colorless.

Besides color, clarity is another important measure of diamond quality. Clarity of the diamond is about the diamond's purity. In other words, a diamond with flawless clarity is a diamond free from imperfection. When checking for clarity, a jeweler looks for clear characteristics or signs of any inclusions. Inclusions might include cloudy spots, dark spots, or crystals. The more inclusions the diamond has, the lower the clarity of the diamond, which has an effect on the worth.

There are varying levels of clarity known as the "clarity scale". The ranges will encompass the top-level clarity such as "F" for flawless to "I3" included #3. For a complete list you can check the Gemological Institute of America (www.gia.org).

The cut of a diamond describes the symmetry of the diamond. For a diamond that is well cut, the symmetry will have brilliance. As one looks at a diamond, you can see how well the brilliance of the stone is by examining its cut and reflection of light. Jewelers can examine the cut of a diamond by looking at the properties of the crown (upper section) and the pavilion (lower section). These sections are further subdivided into subsections called: Table, Star Facet, Bezel Fact, Upper Girdle Facet, Girdle, Lower Girdle Facet, Pavilion Facet and Culet.

There are two ways to determine to determine the grading of the cut: table percentage and depth percentage. Table percentage is calculated by as the longest table measurement divided by the average girdle. The depth percentage is essentially the diamond height divided by the width. These are metrics that provide the proportionality of a diamond, or brilliance.

The carat is the weight of the diamond. In fact, the carat is the measure that is often disclosed to the public. It is generally accepted that the higher the carat weight, the higher the diamond worth. The carat can be broken down to 100-point units. So a diamond with 100 points is a 1-carat diamond.

The four C's aren't the definitive measure that will determine the diamond's worth. However, they are the four most important qualities that a jeweler or individual would need to effectively determine a diamond's worth.

Some facts of Diamonds

Diamonds are carried to the surface by volcanic eruptions. The volcanic magma conduit is known as a kimberlitic pipe or diamond pipe. We find diamonds as inclusions in the (rather ordinary looking) volcanic rock known as kimberlitic. The kimberlitic magmas that carry diamonds to the surface are often much younger than the diamonds they transport (the kimberlitic magma simply acts as a conveyer belt). To ensure they are not converted to graphite, diamonds must be transported extremely rapidly to the Earth surface. It is probable that kimberlitic lavas carrying diamonds erupt at between 10 and 30 kilometer/hour. Within the last few kilometers, the eruption velocity probably increases to several hundred kilometer/hr.

Diamond can be man made or altered to enhance their worth. Either method is legitimate, as long as it's disclosed to consumers.

Synthetics – A diamond is simply crystallized carbon. Subjecting carbon to intense pressure and heat creates man-made diamonds. Most synthetics show a distinctive pattern of color when viewed under ultraviolet light.
Laser Drilling-A laser beam can burn a tunnel through a diamond to reach dark spots or inclusions, which degrade a stone's value. The laser hole is then filled with acid to bleach the imperfection, creating the illusion of flawlessness.
Colored Diamonds- Increasingly popular, color diamonds are quite rare in nature. But irradiation or combination of high heat and pressure can result in diamonds—either natural or synthetic – in a rainbow of tints.
Fracture Filling – The white blemish on the diamond is crack in the stone. Such Flaws can be distinguished when filled with a type of molten glass that refracts light much as a diamond does. Easily detectable, such fillings may be temporary.
Pressure Treating – A homely brown diamond can become a highly prized"colorless" stone when subjected to extremely high heat and pressure. Trained gemologists can usually detect such enhancements.

All natural diamonds are at least 990,000,000 years old. Many are 3,200,000,000 years old (3.2 billion years) how do to know this? Age: from Carbon dating works for very young carbon. You need to use other radioactive decay schemes (e.g., uranium-lead) to date inclusions in diamonds.