GIA is an American Gemological Institute with a global scale comparable to IGI, which was first established in the United States in the 1930s. But the real large-scale development was in the 1950s, which happened to be the period of great development of American industry and consumption. Therefore, there is an urgent need for a unified standard that can be replicated on a large scale to meet people's large demand for diamonds. Therefore, GIA prospectively summarized the previous experience, put forward the concepts of "clarity" and "color" used by merchants in the industry before, and formally put forward the 4C statement in the 1950s, which played an important role in the rapid development of the jewelry industry in the future, and in the following time, it also introduced many instruments for analyzing gems, which facilitated the insiders to identify gems more efficiently.
It can be said that American Gemological Institute is a pioneer in the standardization and popularization of jewelry industry. Its positioning has always been loyal to serving the middle class with the most consumer confidence and the largest number. Therefore, GIA has many fans in the United States, and relatively speaking, high-end jewelry in Europe is used less. What we don't know is that although GIA is a non-profit organization, most of its funds are sponsored by major jewelry companies in the United States. The appearance of its certificate is also in line with the development interests of American jewelers, and it also provides identification certificates for many consumer brands facing the public. For example, the famous American online shop "Blue Nile" focuses on mainstream middle-class men, and basically uses GIA and AGS certificates. When Tiffany took the middle-class route, she used a lot of certificates from American Gemological Institute. With the deviation of self-positioning and brand marketing from GIA mass positioning, I began to use my own certificate.
GIA certificate emphasizes unity. There is a sense of standardization like an assembly line. From the page of the certificate, the star's jewelry and the goods in the street shop all use the same plate making and design. GIA India, GIA America and GIA Hong Kong can't tell their different distribution places. Just like McDonald's and GAP in America, they are the certificates of every policeman, teacher, fisherman and worker in the world. Therefore, it can be said that American Gemological Institute meets the consumption needs of most people in modern industrialization. At the same time, in China, with the reform and opening up, GIA certificate also entered the China market with the influx of American diamonds in the 1990s, becoming one of the international certificates with high recognition in China.
Similar to the GIA certificate, IGI International Gemological Institute, which focuses on the high-end market, and NGTC, the most authoritative national jewelry and jade testing center in China.
GIA is an American Gemological Institute, a non-profit organization, which awards 4C diamonds. IGI is an international gem institute; HRD is a high-level meeting of Belgian diamonds; EGL is the European Gemological Institute; These four international diamond certificates can be used all over the world and only identify loose diamonds.
title
1. American Gemological Institute? : logo; GIA labs.
2.GIA diamond file? : certificate name;
March 7, 2005: Date of issuance. This date also represents the test level and dollar price at that time.
first part
1 ... laser engraving registration form: laser marking "laser number". GIA 13945200 laser number is engraved on the waist of the diamond. The words GIA in black are hollow letters, and the number is consistent with the report number, which is used as proof to identify GIA diamonds.
2. Shape and cutting method: diamond cutting. A circle is a round diamond. For knowledge, please refer to the bright cutting of standard round drill. Diamonds of other shapes have their own unique names, such as emerald cutting; ;
3. Size: diamond size. 4.44-4.48 x 2.76 mm, the diameter (minimum-maximum) * height diameter is allowed to be a range, and the unit is mm;
1. carat weight: diamond weight. 0.33 carat. Carat is the unit of diamond weight, which is called "carat" in Chinese. 1 g =5 carats, 1 carat = 100 integral. GIA is calculated to two decimal places, and the third place is one ninth, for example, 32.89 is 32 points and 32.9 is 33 points; From the investment point of view, the weight above 1 carat has the value of anti-inflation and stable appreciation.
2. Color grade: diamond color. G is the color of this diamond. Gem-grade white diamonds start from D color to Z color. Please refer to the diamond color classification for knowledge, and experts will teach you to choose the diamond color. In addition, pink and other colors are called colored diamonds, such as fancy pink. Colored diamond also has many grades, which will be introduced in detail later.
3. Clarity grade: diamond clarity. VVS2 is the clarity of this exercise. That is 10 times the diamond content under the magnifying glass. GIA classifies diamond clarity into FL, IF, VVS 1-VVS2, VS 1-VS2, SI 1-SI2, I 1-I2-I3 and so on. , decreasing from front to back. Generally, we think that the one with high cost performance is VVS 1-VV. For knowledge, please refer to "Clarity Grade" and "Experts Teach You to Choose Diamond Clarity".
4. Cutting grade: diamond cutting. This is a new comprehensive evaluation. Look at the 4C cut and look at this! In fact, it is a comprehensive measure of many indicators, including symmetry and polishing. The best is the driller. For knowledge, please refer to "Experts Teach You to Choose Diamond Cutting" and "Seeing Diamond Cutting with GIA Database"
Overhead information
1. Clarity characteristics: including. The internal features of some natural diamonds, such as small crystals and cloud-like inclusions, can only be cloud-like under the microscope, but they also affect the refraction of light, thus affecting the quality of diamonds, which is used to prove the naturalness of diamonds; In order to better test its authenticity and fermentation quality.
2. Smoothness: the degree of modification. In other words, after the diamond is cut, the beauty of the diamond is modified. A little bit in life is the type of makeup and hairstyle, which is not as important as the cut subject, but if the degree of modification is better, it will also increase the beauty of the diamond. The degree of modification is divided into two aspects:
A. polishing: polishing. Polishing will increase the brightness of diamonds. But some diamonds have natural features, such as original crystal faces, which cannot be polished off. So if this is a natural situation, don't be too demanding on polishing.
B. symmetry: symmetry. Symmetry refers to whether diamonds are cut symmetrically from left to right, because all diamonds have maximum and minimum diameters, so no diamond is completely symmetrical. It is acceptable that symmetry is higher than good.