Whether you're buying diamonds for yourself or someone else, making the wrong choice can be expensive. Learn how to evaluate the quality of diamonds using the 4 C's so you can choose the right gemstone for a reasonable price.
The first "C" refers to a diamond's carat weight. This measurement is used to describe diamond size. A diamond that weighs 200 milligrams is 1 carat, or 100 points, in size. Since most diamonds are smaller, large diamonds cost much more. If cost is a factor, considering lowering carat size slightly - this usually will result in a significant decrease in the price.
Diamond clarity is also important; most diamonds have small flaws that cannot be seen without magnification. Clarity, which refers to number and significance of flaws, often affects pricing as well. A letter scale is used to grade clarity, and ranges from 'Internally Flawless' (IF), the most expensive, to 'Included 3,' which is the least expensive.
The third "C" describes diamond color. While the most costly diamonds are considered colorless or white, all diamonds contain small amounts of yellow color. The exception to this is the fancy diamond, or Z+ diamond, which usually costs even more than a colorless diamond. Fancy diamonds may be red, pink, orange, yellow, black, blue, or green.
The cut of a diamond refers to its shape. Some people prefer diamonds that are cut in marquise or heart shapes, while others prefer oval or princess designs. Other shapes include emerald, round, and pear shapes.
The cut grade, or cutting style, describes both the diamond's outline and the facet arrangement pattern. Diamond cut depth is also a factor; when diamonds are cut too deeply or too shallowly they sparkle less. Additionally, diamonds with rough facets, or diamonds that are poorly polished, are not as bright or valuable.
Certificates of Diamond Appraisal
Diamond appraisal gives an estimate of the stone's retail value, and also provides information about the diamond's quality with respect to the Four Cs. These certificates are provided by a gemological lab, and are considered to be official documents. The lab verifies that the diamond was not lab-created, and also reports the serial number if the diamond has been laser-inscribed.
Avoid gemologists or labs that are not well-known or do not have a good reputation. Diamond certificates will contain a serial number, and most larger labs offer Internet-based services that allow buyers to verify the serial number and authenticity of the grading certificate. Furthermore, consider buying diamonds that have been certified as to their origins, so as to avoid buying conflict diamonds.
Some well-known labs that grade and certify diamonds are the Gemological Institute of America, or GIA; the International Gemological Institute, or IGI; the European Gemological Laboratory USA, or EGL-US; and the American Gem Society Laboratories, or AGSL. The GIA, located in California, is regarded by many as the gold standard for diamond grading.
The IGI and AGSL are also located in the United States. While the EGL-US is also listed in the U.S., some independent grading laboratories are also known as EGL laboratories and are located outside the U.S. Only EGL-US certificates can be issued for use in the United States, however.
Diamond enhancements
Some diamonds are enhanced to remove flaws or improve their color. For example, clarity-enhanced diamonds are treated to remove obvious flaws. To do this, very tiny amounts of material are placed in the flaw to hide it from view. This material is used in such small quantities that the diamond's weight is not affected.
Different procedures can be used to change the color of a diamond. One of the procedures most often used to change color is irradiation. This is a safe process that uses atomically charged particles to change diamond color. Sometimes, color-enhanced diamonds cost more than an untreated diamond does.
Some diamonds undergo special treatments to remove inclusions. Laser drilling offers the permanent removal of an inclusion without diminishing the strength of the diamond. Laser-drilled diamonds are often preferred over untreated diamonds that contain serious inclusions.
Laboratory results
Some diamonds are also created in a laboratory. For example, high pressure high temperature, or HPHT diamonds are made by subjecting carbon to the same geological processes that result in organic diamonds. A tiny core of diamond is placed on a carbon surface and subjected to extreme temperature and pressure. The result is a diamond crystal.
Another laboratory method used to create diamonds is the Chemical Vapor Deposition, or CVD process. Carbon in a gaseous state is mixed with hydrogen and methane gases. The mixture is then heated and poured onto tiny diamond crystals. Over time, these crystals mature into diamonds.
Look-alike options
Sometimes, buyers prefer stones that look like diamonds to paying the price for the real thing. In these situations, many look-alike options are available to buyers. For example, a Cubic Zirconium, or CZ, is created from Zirconium Oxide. While Cubic Zirconia appear much like diamonds, they lack the impurities of a diamond. The facets and clarity of a stone beneath a magnifying lens make it easier for a trained person to tell the difference.
Another material that looks like diamond is Moissanite. This crystal is made from silicon carbide and is very hard and brilliant. Like diamonds, these crystals sometimes contain inclusions. Since Moissanite is very similar to diamond, it is typically more expensive than CZ.
Simulated diamonds are also manufactured and sold. These are crystals cut to look like diamonds. They are not as strong or brilliant as real diamonds.
Caring for diamonds
Even though diamonds are harder than any other natural substance, they sometimes do chip or crack. When buying a diamond, choose a setting that protects the stone. The most protective settings include four- or six-prong settings; bezel and low-profile channel settings. When not wearing diamond jewelry, wrap it in a soft cloth or pouch for storage to prevent the stones from rubbing against each other.
To clean a diamond, use soap and water. Allow the stone to air dry, and then rub it with a soft polishing cloth. Use an old toothbrush now and then to clean dirt from prongs and edges of the setting. For heavier soiling, use a solution of 25 percent ammonia and 75 percent water with a soft brush. Clean gently; gold settings can be scratched.
Most diamond merchants offer regular programs to have diamonds checked and cleaned. Take advantage of these programs; the jeweler will also check to be sure that the diamond is safely seated in its setting.
Remember, diamonds are a girl's best friend (although guys with class and style also appreciate these lovely gems). Keep that special someone on your arm with the right investment. Or, if you've decided to treat yourself, pick the stone with the 4Cs that best meet your needs - and your budget. You'll be glad you did!