Certificate is the ID card of diamond products. Many people are worried about buying fake diamonds online, but they are not. Regular diamond online stores provide product certificates and pay attention to the transparency of information. On the contrary, many physical stores have no certificates. GIA certificate is the most popular one now, because the diamonds with this certificate have laser anti-counterfeiting labels at the waist. According to the license number, you can check the authenticity online, and there will never be fakes, so it is widely sought after. Of course, the certificate can only be issued in the United States, and the national inspection certificate has the same effect as other international certificates, but it is not so strict in anti-counterfeiting. Internationally recognized as the most authoritative gem certification is GIA certification. In addition to GIA, HRD of Belgium and IGI of American Gemological Association are more authoritative in the world. In our country, it is mainly the national inspection certificate.
1. Gemological Institute of America
GIA was founded in Los Angeles 193 1. It founded and put forward the international scoring system. Headquartered in Los Angeles. The college is trusted by the world in diamond classification and gemstone identification, and is famous for its knowledge and expert position in gemstones. In fact, GIA diamond classification report and GIA diamond processing are considered to be the first gem certificates in the world. Diamonds of all sizes are sent from all corners of the world to the college for analysis and classification.
Gemological Institute of America is an independent non-profit organization. As an authority in the field of gems in the world, it is famous for its justice. The college's breakthrough research and its own education, experiment and equipment research and development process are almost the chronicles of the growth of the jewelry industry.
Since 1953, Richard T. Liddicoat founded and popularized this international diamond grading system, it has become the most respected and authoritative diamond grading appraisal institution in the United States. GIA ensures the credibility of jewelry and diamonds by discovering, imparting and applying gemological knowledge.
2.HRD diamond grade certificate, issued by Belgian Diamond High Council.
Belgian Diamond High Council
The Belgian Diamond High Council is officially recognized as representing the Belgian diamond trading industry. The parliament is headquartered in Antwerp, the world diamond center. The Belgian Diamond High Council issued three kinds of certificates, among which the HRD diamond certificate also contains a complete description of the diamond quality, including the shape, weight, clarity grade, fluorescence, color grade, specification, proportion and polishing grade of the diamond. These unique qualities determine the value of diamonds. It plays an important role in distinguishing whether diamonds are natural colored diamond or imitation diamonds! HRD diamond appraisal report mainly faces diamonds below 1 carat.
3. American Gemological Society (AGS)
American Gemmological Association leads the development of the industry through strict grading standards and providing detailed information. Primary consumers can understand the classification of diamonds through simple digital methods. Diamond processors and diamond wholesalers also use the detailed diamond information provided by the diamond certificate of the American Gemological Institute to buy batches of diamonds around the world.
4. International Gemological Institute (IGI)
The International Gemological Institute in Antwerp is the oldest gemological institute. 1975 has established laboratories in new york, Bangkok, Mumbai and Tokyo. The IGI Diamond Report is essentially a statement, which verifies the authenticity of diamonds with the help of a world-recognized system and provides reliable and correct diamond identity and grade. Each diamond is analyzed by many experienced appraisers using professional instruments to obtain an accurate description of the quality and characteristics of diamond cutting. Explain the details of diamonds in plain language. IGI Diamond Report usually takes 4C (carat weight, color, clarity and cut) as the analysis structure to record the grade and quality of each diamond.
5. European Gemological Institute (EGL)
Guy Margel, the president with a degree in geology, was founded in 1974 and opened the first EGL appraisal center in Antwerp, Belgium. And to help consumers buy diamonds and precious stones as their own responsibility. For more than 30 years, EGL's customers are mainly professional wholesalers, retailers and cutting factories. EGL also provides appraisal and teaching services. In addition, it also provides diamond polishing. The certificate issued by EGL is enough to provide all the information of diamonds, including physical properties such as weight, color, clarity and size, for the reference of the industry and consumers. In the United States and Belgium, EGL certification has a certain professional status and popularity.
6. National Jewelry and Jade Quality Supervision and Inspection Center (NGTC)
The National Jewelry and Jade Quality Supervision and Inspection Center (hereinafter referred to as the Inspection Center) is a national professional quality inspection institution authorized by the relevant competent departments of the state according to law, and it is the authoritative institution for jewelry and jade testing in China. The agency has two testing centers in Shanghai and Shenzhen.
The inspection center provides entrusted inspection services to the society, undertakes national market supervision and inspection, arbitration inspection, import and export commodity inspection, and formulates and revises relevant national standards. It plays a guiding role in standardizing the domestic jewelry market and promoting the healthy development of the jewelry industry.
NGTC Beijing head office
Website:
Address: Building 0/9, Xiao Huang Zhuang Road, Anwai Street, Beijing.
Tel: 0 10-84273700
Chuan Zhen: 0 10-84274845
NGTC shenzheng testing center
Address: 4th Floor, Investment Building, No.2009 Shennan Avenue, Futian Central District, Shenzhen
Tel: 0755-829 12709
Chuan Zhen: 0755-829 127 19
7. Jewellery Testing and Research Center (GJC) of Jewellery Chamber of Commerce of the All-China Federation of Industry and Commerce.
Online certificate inquiry of national jewelry testing institutions
Jewelry Testing and Research Center of Jewellery Chamber of the All-China Federation of Industry and Commerce is a national-level jewelry testing institution approved by China National Accreditation Committee for Laboratories and demonstrated by China National Accreditation Supervision and Administration Committee.
This testing center is tested by professors, researchers, doctors and professional appraisers who have been engaged in jewelry testing for a long time. Have a good test environment and advanced test equipment. Under the standardized management mode, we always adhere to the quality inspection policy of fairness, science, efficiency and integrity, and provide quality services for the society. It is a national first-class jewelry testing authority.
The certificate issued by this testing and research center has been recognized by dozens of countries in the world. GJC address and contact information
Address: Room 703, No.307 Wangfujing Street, Beijing
Tel: 010-652371kloc-0/
Chuan Zhen: 0 10-65236572
8.GAC diamond grading certificate, issued by China Gemstone Association. China Gem Association
Gemmological Association of China is referred to as "Gemmological Association of China" or "GAC" in English. China Gemmology Association is responsible for the quality supervision and inspection of self-discipline products in the national jewelry and jade jewelry industry, and invites local jewelry associations (merchants) to cooperate and assist in the self-discipline supervision and inspection of product quality. Address and contact information of GAC
Website:
Address: Building 0/9, Xiao Huang Zhuang Road, Anwai Street, Beijing.
Tel: +86-0 10-84285027
Chuan Zhen: +86-0 10-84274023
9. GTC Gem Appraisal Certificate issued by Jewellery Testing and Research Center of Jewellery Chamber of All-China Federation of Industry and Commerce. National Light Industry Jewelry Quality Supervision and Inspection Center (GTC)
The center is a metrological certification unit of the State Bureau of Quality and Technical Supervision. The appraisers in the center are composed of jewelry appraisers and appraisers who have obtained the national registered jewelry quality inspector certificate, GIA certificate from the United States, FGA certificate from the United Kingdom, HRD certificate from Belgium and GIC certificate from China.
Adhering to the scientific, fair and authoritative appraisal quality and pursuit, the center personnel have been committed to the nondestructive appraisal of diamonds, colored gems and jade while adhering to national standards and referring to foreign standards.
It has undertaken the tasks of gem appraisal and teaching consultation from consumers, suppliers, sales industries, auction houses, pawn shops and public security courts, and won a good reputation and evaluation in Shanghai and even the whole country with excellent professionalism and technology.
Address and contact information of National Jewelry Quality Supervision and Inspection Center
Website:
Address: No.2, A Datun Road, Chaoyang District, Beijing
Tel: 010-64871971.
Chuan Zhen: 0 10-64870362
10.GIC mosaic diamond grading certificate issued by Beijing Gemstone Testing Center of China Geo University. China Geo University Dida Gem Testing Center (GIC)
With the approval of the Ministry of Geology and Mineral Resources, China Geo University has established 1983 Gemstone Laboratory, 1989 Gemstone Research Institute, 1992 Jewellery Research Institute and 1993 Jewellery Testing Center, which mainly serve the society extensively. At present, it has trained thousands of technical backbones and hundreds of senior appraisers for jewelry quality inspection institutions, production, processing and wholesale units all over the country, and has been praised as the "cradle of treasure education" at home and abroad. Appraising and consulting hundreds of thousands of jewels and jade articles for the society every year.
GIC's address and contact information
Website:
Address: No.29 Xueyuan Road, Haidian District, Beijing
Tel: 0 10-82323039
Chuan Zhen: 0 10-82328093
Box :zhonghui_chen@263.net
Address: Jewelry College of China Geo University (Wuhan), Lumo Road, Hongshan District, Wuhan.
Tel: (027)8748 1009/67883748
Chuanzhen: (027)87482950
E-mail :gic@cug.edu.cn.
How to read "Diamond Appraisal Certificate"
Most jewelry stores or diamond specialty stores sell diamond jewelry with a diamond identification certificate, which is appropriately called the ID card of diamond jewelry. So, how do consumers know the quality of diamonds through diamond identification certificates?
First of all, it is necessary to determine the authenticity of the appraisal certificate. Only the diamond appraisal certificate issued by the jewelry inspection department authorized by the state technical supervision agency has legal effect. These certificates have the measurement certification mark of the national technical supervision department and the seal of the inspection unit. Some testing units have not been authorized by the state, and the appraisal certificates issued by them have no legal effect. Moreover, such certificates are often deceptive, and some detection indicators are untrue, which is likely to become a tool to mislead consumers;
Secondly, check whether the identification number and photo are the same as the style you choose. Since the identification certificate is the ID card of diamond jewelry, the number and photo should correspond to the real thing one by one;
Third, it is necessary to check whether the appearance characteristics of jewelry described in the appraisal certificate are consistent with the real thing. For example, whether the description of diamond's shape, size, total weight and appearance characteristics are consistent with diamond ornaments and whether the fluorescence characteristics are consistent with diamonds;
Fourth, check whether there are signatures of appraisers and examiners on the appraisal certificate. In addition, the appraisal certificate can only be used as a reference for you to buy diamonds, and it does not represent all the quality of diamonds. If you want to buy genuine diamond ornaments, you must know the "4C" standard and go to a reputable jewelry store to buy them.
The difference between GIA certificate in America and national inspection certificate.
Answers to related questions
Replace 1. GIA certificate or laser number is fake?
Absolutely not. GIA certificates are all issued by a diamond, a number corresponds to only one diamond, and a diamond only issues one certificate. GIA will not reissue the certificate of this diamond if it is lost. So consumers can rest assured, but they must go to a merchant with GIA certificate to buy diamonds.
2. Why is the level of international rough diamond certificate different from that of domestic certificate?
This is a very common problem now. Some friends often complain that the clarity level of the international rough stone certificate is "VVS", but it is "VS" in some domestic testing institutions. Or it is clear that the color of the international certificate is "F", but it is only "H" when it comes to national inspection. What's going on here? Many people say that the testing standards of the national inspection are too strict, or that "only the strictest is not the most accurate", because diamonds that can be "VVS" in the national inspection can be done with almost no inclusions under a magnifying glass of ten times ~ because we use a magnifying glass of ten times to pick diamonds, while the national inspection uses a microscope of more than twenty times.
But then again, the strict requirements of the national inspection are aimed at the classification of inlaid diamonds. Please note that this is the classification certificate of "inlaid diamonds", and the classification certificate of loose diamonds made by the national inspection is definitely not so harsh.
3. Why is the certificate of diamond setting so harsh?
This is because the judgment of diamond grade after inlay will be influenced by many factors.
Let's talk about color first: Only naked diamonds can compare colors correctly, because there are many strict requirements for the color grading of diamonds. When grading bare diamonds, the table must be downward than the waist edge with the richest color of diamonds, while the table inlaid with diamonds is upward, so that the fire color of diamonds will largely cover the body color of diamonds. Therefore, it is difficult to accurately judge the color grade of diamonds when the table is facing up. Moreover, after the diamond is inlaid, the color will be affected by the color of the surrounding inlaid metal. If the side is equipped with white metal, the color of the diamond will be white, and when it is surrounded by yellow metal, the color of the diamond will also be yellow ~
Therefore, if the metal inlaid around the diamond is white, the detector will consciously reduce the color of the diamond, so there will be deviation in the color scale judgment.
Please note, however, that this deviation will be greater when the color of the diamond itself is higher.
This is because "H" color diamonds basically have no yellow tone in the color classification of diamonds, while "D-G" color high-grade diamonds do not mean that the higher the grade, the whiter the color, but the more transparent the diamond, so "D" color diamonds are very transparent, not very white, which must be noted, because it can be observed when comparing standard diamonds with colored stones.
Therefore, when judging the mosaic grade of this high-colored diamond, it is very easy to have a big deviation, because as I said before, diamonds in this range are more transparent than others, and there is no yellow tone, and the human eye is far more sensitive to the depth of yellow tone than to the transparency. Moreover, at this time, the diamond has been inlaid, and different styles have different degrees of concealment for the diamond, so it is very difficult.
Therefore, it is not difficult to understand that the color grade of high-color inlaid diamonds will be different from the original bare stones.
Let's talk about clarity first: it is impossible to judge the clarity of inlaid diamonds.
Because the purity grading of bare diamonds is to check the crown, pavilion and waist ~, while the purity grading of inlaid diamonds can only be observed from the crown, and some can check the waist, but due to the limitation of style, it is almost impossible to check the purity of diamonds from the pavilion ~
Anyone who has been engaged in diamond classification knows that many inclusions in diamonds may not be observed from the crown, but they are very easy to see from the pavilion.
There is also a very important point: when a diamond is inlaid, it will definitely come into contact with the metal, that is to say, after the diamond is inlaid, some parts will be blocked by claws, or when it is inlaid, the outer ring of the diamond will be surrounded by metal. At this time, when checking the clarity of the inlaid diamonds, these places covered by metal are simply invisible, that is to say, it is impossible for inspectors to take out the inlaid diamonds for a comprehensive inspection.
Therefore, there are many blind spots in the clarity inspection of inlaid diamonds. In other words, if the clarity grade of inlaid diamonds is "VVS", perhaps the grade of loose diamonds may not be "VS".
Therefore, the clarity level of inlaid diamonds will be very demanding.
4. Will diamonds with GIA rough diamond grading certificate be downgraded when they arrive at the national inspection?
Answer: No.
If all my friends have read it carefully, I believe they will have a good idea of how to judge the level of national inspection.
The reason why the national inspection and some domestic testing institutions downgrade some diamonds with international certificates is not because the inspectors of the national inspection are incompetent, because they can't judge the grade, so they will only be downgraded, or because the inspectors have no "relationship" with the testing institutions, they will downgrade diamonds with sufficient grade.
When domestic testing institutions determine that the inlaid diamond is the one on the international certificate, they will refer to the grade on the original stone certificate and make their own grade judgment. I believe that if the rough diamond grading certificate is also issued in China, the grade will definitely not be very different from GIA's rough diamond certificate, but if it is inlaid, there will still be some differences. I believe that friends who have carefully read the above reasons will understand that when domestic testing institutions confirm that the inlaid diamond is this one on the international certificate, they refer to the grade on the original stone certificate to make their own grade judgment. I believe that if the rough diamond grading certificate is also issued in the national inspection, the grade will definitely not be very different from GIA's rough diamond certificate, but if it is inlaid, there will still be some differences. I believe that friends who have carefully read the above reasons will understand.