GIA is short for the Gemological Institute of America. Robert M. Shipley, founder of Gemological Institute of America, founded the GIA in Los Angeles in the United States in 1931, initially using night schools and correspondence to train jewelers on the wholesale price. In 1953, GIA opened the first place in New York Laboratory Laboratory, began issuing diamond appraisals and then another two laboratories in Santa Monica, Santa Monica, CA, and downtown LA, formally known as Gem Trade Laboratory .INC (GTL), a gemstone appraisal firm under the GTL GIA full appraisal not valued. Is the world's earliest creation of the International Diamond 4C standard authoritative appraisal agencies, adhering to a fair, scientific and rigorous approach to the identification of each diamond are in strict accordance with the 4C standard for grading, therefore, with the GIA certificate of diamonds in the world of diamonds The transaction by the vast number of consumers trust, respected, is currently the most authoritative international diamond certification body. GIA's diamond certificate is divided into three categories: 1: The GIA Diamond Grading Report, often referred to as the GIA Grand Prize, can be issued for any weight of diamonds, but mostly carats, a detailed diamond parameter report, usually with a 350x magnification of the front and back of the diamond Clarity sketch map. Taking into account the failure of laser marking safety, and the future re-wear around the waist loss. GIA certificate is not necessarily marked with a laser on the waistline. 2: The GIA Diamond Dossier, often referred to as the GIA Smaller, is usually a small 1 carat diamond. Compared to a large card, lacking an enlarged internal sketching, all GIA Diamonds are laser-coded on the waistline. 3: GIA Colored Diamond Grading Report GIA certificate issued specifically for color diamonds, the basic content and the same GIA certificate, and color diamond grading system is based on the relative concentration of diamond color. In a given light source and comparison environment, use a well-matched alignment group to find the diamond's characteristic color and set the color level. GIA uses a specific level of terminology to define the range of color appearances: Faint, Very Light, Light, Fancy Light, Fancy, Fancy Intense, FancyDark, Fancy Deep, Fancy Vivid. GIA Clarity Rating: FL-IF Clarity: "FL" = No class: No level of inclusions or blemishes. A perfectly flawless diamond. IF = No class within the flaw: No intrinsic flaws. This level of clarity of the diamond outside the diamond has a slight scratch, but the interior is completely flawless. Both types of clarity diamonds are extremely rare. Please note that the domestic diamond grading certificate will not be issued IF level, the highest is VVS. VVS1-2 Level Clarity: Very Small and Very Low VVS Level 1 Diamond Clarity is slightly better than VVS2 Diamond. VS1-2 Level Clarity: Micro-Diffuse Level .VS1-level diamond clarity slightly better than the VS2 level diamond clarity. The contents of these diamonds are invisible to the naked eye. The price is several points below the high level of clarity. This clarity class of diamonds is very beautiful and of high value. SI1-2 Clarity: Slightly imperfect .SI1-level diamond clarity is slightly better than that of a SI2-grade diamond. This level of clarity diamond inclusions professionals can see with a magnifying glass. This level of clarity of the diamond has a unique price and value. Cut Grade: It refers to the evaluation and explanation of the proportion and modification of finished diamond. It is very important to directly affect the overall effect of diamond brightness and fire color and the balance between the two. GIA certificate system, Excellent is perfect, Very good is good, Good is good, Fair is acceptable, Poor is poor. Both are not considered when buying loose diamonds. Cut this measure is the only one by the technical staff to operate, and make the beauty of diamonds can be an important factor in re-promotion. Cut diamond face size, proportion, symmetry (Symmetry) and Polish (Polish) effect, combined with changes in the angle of the cutting surface, and the resulting Diamond Diamond gloss can have brightness, fire and flashing. The best standard for cutting is to expose these three indicators on average. GIA is how to develop cut-level classification After years of research and accumulated data analysis, GIA introduced the most complete set of systematic methods for grading and grading. As the originator of diamond grading, GIA introduced the diamond grading classification from the end of 2005 to the market and Consumers have come to the simpler and more obvious assessment criteria for diamonds, and the GIA's classification has to be done with many specialized instruments and equipment. Therefore EX EX 3EX in particular the GIA certificate of the diamond, the overall shape or the overall feeling is perfect. Fixing (Finish): polishing the final evaluation of the diamond process. Divided into two parts of the surface polishing and symmetry. Polish is mainly to determine whether there is any obvious WHEEL MARK or BURN MARK. The evaluation of polishing: EXCELLENT perfect, VERY GOOD good, good GOOD, FAIR is acceptable, poor POOR. Symmetry: a part of cut evaluation. The evaluation is divided into the main symmetry and secondary symmetry to evaluate the main symmetry defects have no significant impact on the appearance of the diamond, the secondary symmetry defects on the aesthetic appearance and value of little. The main symmetry defects include: girdle contour is not smooth, countertop eccentric, the bottom eccentric, wavy girdle or inclined table. GIA diamond grading system is divided into EXCELLENT perfect, VERY GOOD good, good GOOD, FAIR is acceptable, poor POOR. Fluorescence (Fluorescence): Fluorescence reaction is the diamond by external energy stimuli, usually refers to the time of exposure to ultraviolet light, the reaction of light color. Divided according to their strength: NONE did not, FAINT weak, MEDIUM moderate, strong STRONG, VERY STRONG so strong five. Which FAINT does not record its fluorescence reaction color. Fluorescent knowledge: Fluorescence is a natural phenomenon of diamonds, blue fluorescence can enhance the brightness of diamonds, yellow fluorescence may reduce the whiteness, so with fluorescent diamond also depends on what kind of light. A blue-fluorescent diamond will appear whiter than its non-fluorescent diamond at the same color level, with a little more blue light at the time of the fire, but this depends on the size and fluorescence of the diamond. Internationally determine the diamond color, it is necessary to deduct some of the blue fluorescent whitening fraction, that is, if the two diamonds are F color, a Strong Blue fluorescent, are the same international agency certificate, A very large possibility is that the original color of the diamond with fluorescence is higher than the other one without fluorescence. However, the fluorescence of yellow is exactly the opposite. The domestic national gem testing center does not grade the fluorescence comment, most of the diamonds currently on the market are not specified, with the exception of international certificates. Clarity Characteristics: The internal features of some natural diamonds, such as crystal crystals and cloud-like inclusions, are internal features that can be further observed under a microscope to prove the naturalness of the diamond. Types of diamond inclusions include Crystal, Feather, Cloud, Pinpoint, Internal Graining. Additional Inscription: Diamond's brand name or self-attached private message can be engraved on the waist of a diamond according to your requirements. Together with the diamond identification number, it becomes the unique symbol of this diamond. If there is no extra lettering, Marking.