Why Should I Shop At AGS Member Stores?
American Gem Society membership is your guarantee that you are doing business with jewelry professionals: a staff and store that is committed to on-going gemological training, customer service of the highest caliber, and, above all, integrity.
AGS members are respected leaders in the jewelry industry, and long-term members of your community. Your satisfaction is important to them because they know that, to build trust and confidence, they must provide you with the very best service and information available. Their success is enhanced by your satisfaction.
When you shop for diamond jewelry or for a very special diamond, the first thing to look for is the firm's membership in the American Gem Society.
What Is The American Gem Society Grading System?
American Gem Society has developed the AGS Diamond Grading System based on three value factors: cut, color, and clarity, with each evaluated on its own 0 to 10 scale. The scale begins at 0, the highest grade, and goes down to 10, the lowest. The three factors are expressed separately along with the carat weight of the stone for the final AGS Grade.
What Is Cut and How Is It Graded
Cut is the only value factor that can be controlled by human hands. The qualities of a diamond in the rough can only be brought out by the work of a skilled artist. Before you see a sparkling diamond under the lights in your local jewelry store, it has already been shaped to stringent specifications by a skilled artisan, and given its beautiful polish.
How Is Color Graded?
Distinguishing color is not as easy as it seems at first glance. With diamonds, even small differences in color can make a big difference.
A colorless diamond is graced with that glorious display of light and prismatic colors for which diamonds are so highly prized. The presence of color then goes from barely discernable near colorless to light yellow or brown. Beyond a certain point, or with other colors such as green or red, a diamond is considered a fancy color.
Unless a diamond is a fancy color, the AGS Color Grading System places it on a 0 to 10 scale, to show the range from the rarer colorless diamonds to those diamonds with varying tinges of yellow or brown.
To find an accurate color grade, an AGS member jeweler compares each stone to a set of Masterstones which have been graded according to AGS standards. It is part of an AGS member store's commitment to maintain a minimum of three, and frequently five, masterstones specifically for grading purposes. Ask any jeweler to show you the Masterstone Set by which their diamonds are color graded.
What Is Clarity and How Is It Graded?
Clarity characteristics are divided into two main groups: inclusions and blemishes. Inclusions are inside the stone; blemishes are on the surface.
There are many kinds of inclusions. Some are quite well-known and may be familiar to you: feathers, clouds, cavities, and the presence of crystals within the diamond.
Blemishes include characteristics such as abrasions, nicks, pits, scratches, and others as well. Since blemishes affect the polish, they are often counted under cut rather than clarity. (If so, they are not counted twice.)
Two tools are used for judging a diamond's clarity: magnification and the human eye. All American Gem Society grades are determined by a professional using a special stereoscopic zoom microscope.
If magnification to the tenth power under a gem microscope reveals no inclusions, the diamond earns a Clarity Grade of 0, the grade for the most exquisitely clear diamonds. If magnification reveals that light returning to your eye may be affected by one or more inclusions, the professional AGS jeweler determines the appropriate grade along the continuum of 0 to 10.
In addition to the microscope, the grader's skilled eye is another tool for judging clarity. If your jeweler can see a clarity characteristic without magnification, you can too. The presence of such a characteristic could cause the grade of the diamond to drop on down below the middle of the scale.
Remember, most diamonds have some inclusions. This doesn't mean that a diamond with an inclusion isn't a quality diamond. It does show that your AGS jeweler wants you to have all the facts necessary for you to make an informed decision.
What Should I Know About Carat Weight?
You're probably familiar with the term carat, the unit of measurement used to indicate the weight of gemstones. (This should not be confused with karat, the term jewelers use when stating the relative fineness of gold.)
You want to be sure your jeweler is clear about the terms that are used in reference to the weight of a diamond. One carat is equal to 1/5 of a gram. For diamonds less than one carat, weights can be expressed in terms of halves and quarters (as long as they are at least half or a quarter). For more precision, the carat can be divided into 100 points. Thus, a 10 point diamond is 1/10 of a carat.
Since small variations in weight can make big differences in price, you want to be sure that your diamond has been weighed in a precise and repeatable manner. AGS member jewelers weigh unmounted diamonds on an electronic scale capable of weighing as accurately as .002 (two one-thousandths) of a carat. No jeweler should be reluctant to show you how the weight of the stone you are looking at was arrived at.
What About A Certificate?
When you are shopping for a diamond, you may hear that a particular diamond is "certified" This usually refers to a quality analysis report issued by the Gemological Institute of America's Gem Trade Laboratory (GTL).
The Gemological Institute of America (GIA) is well respected in the jewelry industry. The Institute provides much of the gemological training for jewelers, including most members of the American Gem Society. But GIA does not "certify" diamonds.
GTL quality analysis reports reflect some of the factors which help to determine how a diamond is valued. A color grade, a clarity grade, and a precise weight are each stated on the report. There is, however, no cut grade.
As you look for assurances, and you have every right to expect some assurance when you make a major purchase, your best guarantee is the American Gem Society member store where you shop for your diamond AGS diamond graders are trained in the use of the GIA diamond grading scale and can use that scale appropriately should you want to make comparisons. And AGS members stand behind the value statement they issue regarding each and every diamond they sell.
In the end, remember that AGS member stores are accountable to you, the customer. You can rely on the AGS grades and weights that establish the value of the diamond you are considering. You don't need a "certificate"