A certificate, or diamond grading report, is a professional evaluation of a diamond's quality and characteristics. This certificate, when it accompanies a diamond, serves as proof of the diamond's identity. Frequently the certificate contains a 'plot' or diagram of all the characteristics that are found in the diamond. Please note: a certificate is not the same thing as an appraisal. A certificate describes the quality of a diamond, but it does not place a monetary value on the gem. If you are seeking to insure your diamond, you will need to get a separate appraisal; most appraisers, though, will base their appraisals on the stated quality of the diamond that is found on the certificate. This evaluation can be performed by anyone with the appropriate training and lab equipment, but it is most trustworthy and most useful when it is issued by an accredited independent lab that is not involved in the sale or purchase of the diamond. The Gemological Institute of America (GIA) and the American Gem Society (AGS) are the two most widely regarded and recognized labs in the world; all Mondera diamonds featured in our Diamond Store are certified by one of these two labs. Because some other labs are not as strict with their standards, and many err on the side of leniency to please the retailers, we recommend always buying only GIA- or AGS-certified diamonds. Always ask for credentials of the certifying lab, and choose carefully. All certificates contain the following information:   A certificate number that is unique to the diamond   A description of the shape of the diamond   The carat weight of the diamond   The color of the diamond   The clarity of the diamond   The length, width and depth of the diamond in millimeters   The quality of the diamond's polish and symmetry   The total depth percentage and table percentage of the diamond   A description of the girdle's appearance   A description of the presence or absence of fluorescence in the diamond Some certificates may also contain the following additional information:   An assessment of the quality of the diamond's cut: Currently only AGS offers this assessment on their certificates.   A plot of the clarity characteristics in the diamond: Some diamonds weighing 0.70 carats or less are accompanied by dossiers, rather than a full grading report; these dossiers provide a written description of the main characteristics rather than a plot, but they are still considered to be equally valid proof of the diamond's identity. In fact, all diamonds that are accompanied by GIA dossiers have their certificate numbers laser-engraved on the girdle as further proof of their identity.   A section entitled "Comments" that is listed directly underneath the description of the diamond's fluorescence on a GIA report, or underneath the carat weight on an AGS report: Usually this section simply describes particular characteristics of the diamond's clarity, and it is of no concern. However, for some diamonds, the comments may refer to "crown angles;" this means that the angles of the diamond's crown lay outside of what is generally considered acceptable for that particular cut. Just ask for one: In many jewelry stores, they're provided upon request. A quick rule of thumb: If a jewelry store offers to sell you a diamond without a certificate, keep in mind that it means you are buying the diamond based only on the salesperson's claim about its quality, and that a trained gemologist or even other jewelers may disagree with the salesperson's assessment. That means that, by independent laboratory standards, you may not be buying what the salesperson claims, so the diamond may not be such a bargain in the end. Wherever you choose to get your diamonds, always buy from someone you trust and get a report from a professional lab to ascertain that you've gotten what you paid for. There is no physical difference between a diamond that is certified and one that is not. A certificate does not change the nature of a diamond in any way. The difference between a certified and an uncertified diamond is that, with the certified diamond, you have tangible, legal assurances as to the particular nature and quality of the diamond you are purchasing. A certified diamond comes with a diamond grading report guaranteed by an accredited gem lab. This report assures the customer that the diamond is independently recognized as possessing all the qualities specified by that report. All the diamonds featured in the Diamond Store on our site are certified by either GIA or AGS. When you buy a certified diamond, you are getting a diamond with beauty and pedigree. On the other hand, an uncertified diamond is not accompanied by a diamond grading report, and therefore its stated quality is based only on the word of the seller. An uncertified diamond is not necessarily a bad diamond; certainly, it can be as beautiful as its certified counterpart. However, we encourage our customers to buy certified diamonds for the following reasons:   Shopping for certified diamonds allows you to make an informed choice about your selections, and to comparison shop. You can compare one diamond with a particular weight and quality with other diamonds of similar weight and quality to determine which is the better value.   With uncertified diamonds, it is difficult to determine whether the quality assessments of one jeweler will be as stringent and precise as the judgments of other jewelers; that is, not all jewelers may agree about the quality of an uncertified diamond.   A diamond grading report adds value to a diamond. The quality assessments made by independent labs, such as GIA or AGS, are recognized worldwide. These quality assessments are used by appraisers to determine the insurance or replacement value of your diamond.   If you purchase an uncertified diamond, there is no guarantee that the appraiser will appraise your diamond at the same level at which the jeweler who sold it to you did. A quick note on how reports from various independent labs compare with one another: GIA and AGS are considered the industry leaders, and the final word on gem quality, among diamond dealers worldwide.   While plenty of other independent labs exist, some are a bit lax in their assessments of diamond quality and do not command the same respect for consistency and quality of grading that GIA and AGS do. For this reason, if you are in the market for a diamond, make an effort to buy only GIA- or AGS-graded diamonds.   A diamond grading report adds an increased comfort-level to your purchase. Because the quality of your purchase has been independently verified, you can feel assured that you have made a wise purchase and that you have received exactly what you have paid for.