Glossary of Terms:
American Gem Society
The American Gem Society is a not-for-profit trade association of fine jewelers, jewelry manufacturers, and suppliers in the
Canada.These members are dedicated to consumer protection, ethical business practices, and the development of superior gemological skills and knowledge. Founded by Robert M. Shipley in 1934, today the American Gem Society includes 1,300 retail, supplier, and sustaining members firms and nearly 2,000 individual titleholders.
Gems
Most gems are minerals that have been chosen for their beauty and durability, then cut and polished for use as human adornment. However, there are exceptions. While most gems are minerals, pearls and amber are organics, that is, created by living organisms.
Colored gemstones range from the ever-popular ruby to the rare chameleon-like Alexandrite, and each type of gemstone can range in color, price, durability, and quality. For many colored stones, the intensity of the color is the key to value.Your American Gem Society jeweler can introduce you to an array of gemstones that will please your eye and accent your wardrobe.
Recertification Exam
To qualify for membership and ensure excellence, individual American Gem Society titleholders and designees must pass stringent examinations on diamonds and colored gemstones. All Registered Jewelers, Certified Gemologists, Certified Gemologist Appraisers, and Certified Sales Associates are required to be recertified annually.
Opinion
For an independent opinion of quality and/or value, locate an Independent Certified Gemologist Appraiser Firm of the American Gem Society (ICGA). The ICGA member not only meets the rigid Appraisal Standards of the American Gem Society, but also employs a credentialed appraiser —Certified Gemologist Appraiser (CGA) — who has completed advanced studies in appraisal methodologies.
Membership
Only 5% of all jewelers, designers, appraisers, and suppliers have met the exacting standards required for membership in the American Gem Society. In order for a firm to become a member of the American Gem Society, it must meet a list of rigid requirements.
The firm owners, principals, or employees must have completed an accredited or graduate program from the Gemological Institute of America or Gem-A (Gemomological Association of Great Britain).In addition, they must have completed further studies with the American Gem Society.
The firm must hold a reputation for unquestioned integrity in the business community and must be operated in a manner that enhances the confidence of the public in the jewelry industry.
The owners and principals must demonstrate that they are genuinely interested in high business ethics and that the firm exemplifies this belief.
The firm must have been in business for at least two years and must demonstrate financial stability.
Creditials
Upon completion of rigorous courses and exams, the American Gem Society confers titles according to the level of gemological education and experience of members.These titles are renewed annually with a Recertification Exam.
Diamonds
In terms of appeal, diamond is the world’s most popular gems. It has great brilliance, plus the delightful quality known as fire or dispersion (the ability to turn white light into a rainbow of colors). Diamond is graded on four qualities, commonly known as the 4 Cs: Cut, Color, Clarity, and Carat Weight.
Equipment
When American Gem Society titleholders evaluate an unmounted diamond according to American Gem Society Standards, they weigh the diamond to exacting standards and assign grades for cut, color, and clarity under controlled conditions using specialized instruments and the latest technology according to the strictest guidelines established by the American Gem Society.
The American Gem Society Diamond Grading Standards
The American Gem Society Diamond Grading Standards evaluate three of the four value factors — cut, color and clarity — on the society’s own 0–10 scale. The scale begins at 0 (zero), the highest grade, and goes down to 10, the lowest. The three factors are expressed separately along with the fourth factor, the carat weight of the stone, for the final AGS Grade.
The American Gem Society Laboratories was established to provide consumers with credible, yet unbiased, analysis of a diamond. The AGS Laboratories bases its analysis on the American Gem Society's Diamond Standards and maintains the most stringent criteria in the industry.
Only an accredited AGS member or the American Gem Society Laboratories can issue a grading report that uses the AGS Diamond Grading Standards.
Cut
Cut is much more than just the shape of the diamond (round, oval, square, etc.).
Diamonds must be cut and polished in order to release their true beauty. It is only when the smooth facets are polished on the diamond that it truly comes to life. A little knowledge about how diamonds are shaped in nature and what a cutter must do to make them sparkle will help you understand cut. Of all the 4 Cs, it is cut of a diamond that will make a person fall in love with it. A diamond can be flawless and colorless, but it will not be beautiful if it does not dance with light. Good cutting also can disuise lower color and can override lower clarity due to dazzling light return. There is value in that, too.
The cutting process is time-consuming, requires specialized tools, and demands expert training and craftsman skill levels. The cutter must study the rough carefully, set the angles properly, and polish carefully, or the final product will appear lifeless. For instance, if the pavilion of a stone is too deep, the diamond will appear dark and dull. If the pavilion is too shallow, reflections of the gridle will be seen through the hole. If the table is too large, the resulting surface reflection will be distracting and the fire (rainbow colors) will be reduced. If the girdle is too thick, the gemstone will be difficult to set in a mounting and to keep secure. If either the girdle of the crown is too thin, the gemstone will chip easily. It is important to remember these causes and effects; any one of them will affect value and possibly durability. Without advance training, it is difficult to tangibly identify any of the particular faults, but knowing they exist will assist in understanding the beauty of diamonds.
When creating the finished diamond, there are reasons why a diamond cutter makes compromises. As the cutter strives for the maximum weight retention from the rough and tries to create the largest diamond possible, he may choose to sacrifice the best balance of light return. This is truly a case of "Beauty is in the eye of the beholder." Good cutting is the key to a beautiful diamond and the most obvious factor a person can appreciate.
Symmetry and polish are collectively described as finish, but each is an important separate element in a beautifully cut diamond. Symmetry consideratons include the size, alignment, and matching of the individual facets. Polish refers to the surface condition of the diamond. For instance, if polished too quickly, polish lines might appear as minute scratches on a facet's surface. It is even possible for the cutter to burn the diamond. (A burned facet has a milky appearance — as if the diamond needs cleaning.) These characteristics are evaluated and rated on their overall impact on the beauty of the diamond. Most polish characteristics can be removed easily with repolishing and with very little weight loss. Again, the American Gem Society grade scale for finish is 0-10, with 0 being the best.
The term ideal cut may be familiar. This sometimes is used to describe a diamond that has been but with exceptional thought to proportions and finish. There have been and will continue to be changes and opinions on one true ideal, but there is no denying the exceptional beauty of an AGS Ideal™ diamond. This means the diamond's performance, proportions, and finish — three elements of the cut grade — all qualified for an AGS Ideal™ grade. The American Gem Society grades cut on a numerical scale of 0-10, the highest cut grade being AGS 0 (zero).
The American Gem Society has the most internationally recognized system for grading the cut of a round brilliant diamond. Many professional laboratories do not address the overall cut grade, and others have their own parameters for ideal. The different laboratories publish their own standards. Access to these standards is available through the web sites for AGS Laboratories at www.agslab.com or the GIA Laboratory at www.gia.edu.
Color
A truly colorless diamond is extremely rare. Most diamonds possess varying degrees of yellow, brown, or gray, and small, subtle differences in color can make a substantial difference in value. Although increasing shades of yellow can reduce the value of a diamond, this does not necessarily reduce its beauty. If a diamond is well cut, the diamond’s light performance often will disguise certain degrees of coloration. Unless a diamond is a fancy color (or any color other than colorless to light yellow, brown, or gray), the American Gem Society Color Grading System places it on a 0 to 10 scale, 0 being colorless. To accurately and consistently grade color, an American Gem Society trained grader will use special lighting to compare the diamond being graded to a set of American Gem Society Master Color-Comparison Diamonds, which have met exacting standards of cut, color, clarity, and carat weight. The diamond is viewed face down and reassessed face-up for the most accurate and consistent grade.
Clarity
Clarity is the evaluation of a diamond's internal and external characteristics. The fewer inclusions or blemishes, the more rare the diamond.Inclusions are internal, that is, inside the diamond. Two of the most common inclusions are crystals and feathers.
Carat Weight
Comparing the value of stones by weight is like comparing the value of paintings by size. A wall-sized canvas by an unskilled artist may be bigger than a miniature by Rembrandt, but it will not be worth more. The standard used to measure diamond weight is the carat. A carat equals 1/5 of a gram (or 1/142 of an ounce).Each carat is further divided into points, each point representing 1/100th of a carat. While weight may be less important of the four Cs in determining value, it may be the easiest of the four Cs to gauge accurately and is the most objective. All that is required is a precisely balanced scale capable of weighting extremely small weights. Yet, despite the ease of measurement and the relative unimportance of diamond weight, there are some facts you should understand about weight and price.
First, as diamonds increase in size, their cost tends to increase exponentially rather than arithmetically. Thus, a one-carat diamond may cost more than twice as much as a one-half carat stone of equal quality.Also, as previously stated, weight does not always enhance the value of a diamond. In fact, when a stone is improperly cut, added weight may serve only to reduce its brilliance. For these reasons, you should consult with an American Gem Society titleholder regarding the question of carat weight, especially as it relates to the quality of the diamond's cut.
Magnification
Most jewelers use a magnification device called a loupe to examine diamonds and fine gems.However, American Gem Society member jeweler uses a binocular microscope that magnifies the diamond by ten times to accurately and precisely evaluate each stone.
GIA
The Gemological Institute of America (GIA) is the world’s largest nonprofit institute of gemological research and learning.For more information, visit:www.gia.edu
The American Gem Society Conclave
The American Gem Society Conclave is the premier educational conference in the jewelry industry. The multi-day event features education sessions on gemology, business, marketing and sales. Conclave attendees have access to world reknowned business speakers, education and networking sessions and the up-to-date technology advances.
Spectra
The quarterly magazine publication for American Gem Society Members.
AGS titleholder
The American Gem Society bestows titles on worthy professionals who have passed a rigorous set of examinations.Our Certified Gemologist Appraiser (CGA) title is the most highly regarded in the industry. Earning the CGA title requires beyond the Graduate Gemologist diploma advanced training and experience in identification and valuation of gemstones and jewelry. All CGA titleholders also must pass an annual Recertification Exam to maintain this prestigious title. The American Gem Society confers the following titles:
Registered Jeweler (RJ) 
Registered Supplier (RS) 
Certified Gemologist (CG) 
Certified Gemologist Appraiser (CGA) 
(Certified Sales Associate) 
Individuals who have successfully completed the Graduate Sales Associate course, and The AGS Professional module and are actively selling in an American Gem Society Member Firm. This designation also requires the successful completion of an annual Recertification Exam.
Colorvision Screening
The American Gem Society offers a quick and effective Colorvision screening that is designed to evaluate color proficiency and identify possible deficiencies. Colorvision screening is available to members and non-members alike and is administered by AGS staff members at various industry tradeshows, including AGTA, JCK —
Please view our Calendar for a list of scheduled testing.
Advanced Personal Property Appraisal course
The Advanced Personal Property Appraisal course is offered through the Jeweler’s Education Foundation of the American Gem Society. It is available to all individuals interested in the professional field of appraising. The three-part home-study course covers appraisal theory and the legalities and guidelines of professional appraising, takes approximately 3 to 6 months to complete and concludes with a proctored exam.
Successful completion of this three-part course is required of the firm principal of an ICGA firm. For more information, contact the Education Department at 866-805-6500 x1034 or mspence@americangemsociety.org.
Graduate Sales Associate course
The Graduate Sales Associate course is one of the most comprehensive sales associate training programs available in the jewelry industry. Course participants receive initial training on product knowledge, sales techniques and success strategies. The seven-chapter home-study course contains pertinent facts on diamonds, colored stones, pearls, metals, watches and period jewelry, along with information about the jewelry industry and the importance of good customer service and ethical business practices. Upon successful completion of a proctored final exam, the associate is awarded a Graduate Sales Associate Certificate from the Jewelers Education Foundation of the American Gem Society.
