GIA belongs to the only certificate recognized all over the world, while TNF belongs to the company.
There is a set of standards for grading solid diamonds, all of which are colorimetric stones. This set of standards is common all over the world, but there will be some errors or different standards. ?
The national inspection is one level higher than GIA, and GIA is one or two levels higher than IGI and HRD. Although the standard of national inspection is stricter than the four international certificates, it does not mean that our national inspection certificate is the best. In fact, our national inspection certificate is not recognized by them internationally! ?
According to common sense, the standard of TFN can't be higher than our national inspection, but it remains to be studied whether it is a bit boastful to grade itself.
Extended data:
GIA is a non-profit organization, and its funds are donated by people in the jewelry industry. Its main service scope is jewelry appraisal and professional knowledge education and research, which is deeply recognized by the global jewelry industry. GIA is the founder of promoting the internationalization of diamond certification.
193 1 year, Mr. Robert m. shipley founded the GIA Gemological Institute in the United States. Up to now, GIA has 14 teaching institutions around the world, providing professional courses such as research, sales and appraisal to train high-quality jewelry practitioners.
It has also achieved GIA's high reputation in the industry and made the public always lead the world in trust and professionalism. Nowadays, the 4C standard proposed by GIA is also a common standard in the international jewelry industry.
Internationally recognized diamond grade certificates are as follows:
International Gemological Institute (IGI) ——IGI Diamond Grade Certificate
IGI, the International Gemological Institute, is the world's largest independent gem identification laboratory and gem research and education institution. It has 65,438+05 laboratories and schools in major diamond trading centers and central cities around the world (Antwerp, new york, Toronto, Dubai, Tokyo, Hongkong, Tel Aviv, Los Angeles and Mumbai), and gemologists from more than 96 countries around the world receive laboratory, education and scientific research services from IGI.
Rich experience, professional advice and long-term reputation for reliability and integrity make IGI synonymous with reference standards in jewelry industry. IGI has developed patented technologies such as laser lettering and darkroom photos in the process of identification for decades, and initiated and popularized the 3EX cutting evaluation system. For a long time, it has been a global leader and standard setter in the field of gemology.
Gemological Institute of America (GIA) ——GIA Diamond Grade Certificate
Gemological Institute of America is an independent non-profit organization. The college's breakthrough research and its own education, experiments and equipment are all open.
The development process witnessed the chronicle of the growth of the jewelry industry.
GIA diamond classification report and GIA diamond processing are considered as world-famous gem certificates. Diamonds of all shapes and sizes are sent from all over the world to the college for analysis and classification.
Belgian Diamond High Council -HRD Diamond Grade Certificate
The Belgian Diamond High Council is officially recognized as representing the Belgian diamond trading industry. Its headquarters is located in Antwerp, the world diamond center.
HRD diamond color certificate focuses on the detailed characteristics that determine the value of colored diamond, such as color description, color design and luminescence. It plays an important role in detecting whether diamonds are natural colored diamond or imitation diamonds.
American Gemological Society -AGS Diamond Grade Certificate
American Gemological Society leads the industry by strict grading standards and providing detailed information. Primary consumers can understand the classification of diamonds with simple numbers and methods.
Diamond wholesalers and processors often use the detailed diamond information provided by AGS certificates to buy diamonds in batches around the world.
European Gemological Institute -EGL Diamond Grade Certificate
EGL was established in 1974, and its customers are mainly professional wholesalers, retailers and cutting factories. Its mission is to help consumers buy diamonds and precious stones.
In the United States and Belgium, EGL certification has a certain professional status and popularity. The appraisal certificate issued by it is enough to provide all the information of diamonds, including physical properties such as weight, color, clarity and size, for the reference of industries and consumers.
In 2008, EGL established an independent third-party diamond appraisal laboratory in Hong Kong, named EGLAsia, to provide safer and faster diamond appraisal services for Asian diamond customers. EGL Asia has set up two offices in Chinese mainland: the Shanghai office and the Shenzhen office.
National Jewelry and Jade Quality Supervision and Inspection Center -NGTC Diamond Grading Certificate
The National Jewelry and Jade Quality Supervision and Inspection Center (hereinafter referred to as the Inspection Center) is a national professional jewelry and jade quality inspection institution authorized by the relevant competent departments of the state according to law. The diamond grading system used in national inspection also follows international practice, and diamonds are graded in turn according to cut, color and clarity.
American GemEx? Systems company Gemex company -GEMEX? Concurrent beauty certificate
GemEx？ Beauty certificate is a certificate to rate the brilliance (white light), fire color (colored light) and sparkle (flashing) of diamonds.
GemEx company is an American diamond optical appraisal institution, which pioneered the scientific measurement concept of diamond light efficiency certification. It is the first to use visual indicators (the beauty of diamonds) to evaluate and compare diamonds.
authority
GIA five-star ★★★★★★★★★
IGI five stars ★★★★★★★★★
Five stars in HRD ★★★★★★★
At this point, the three companies have nothing to doubt, and they are all international authorities. The international diamond grading standards are maintained by these three companies, and the certificates issued by them occupy the vast majority of the market.
information quantity
The diamond information part of the international certificate will be described in detail from the size, weight and shape of the diamond to each cutting index, and the accuracy of the description is extremely strict. For example, the pavilion depth ratio is 48.3%, the cutting grade will be described in several aspects, and the color clarity grade is more accurate to a certain extent.
In addition, the certificate can also be attached with a detailed chart of the internal defects of the diamond as an aid to the clarity rating.
GIA five-star ★★★★★★ ★:
GIA sets the highest level of diamond clarity as F (immaculate level). Different from the familiar IF (immaculate level) level, GIA requires not only that there are no flaws inside the diamond, but also that the surface of the diamond should not be scratched or even worn. Therefore, we should be extremely careful when setting and wearing the diamond, otherwise it will easily lead to inconsistent certificate levels.
However, GIA can only be divided into polishing (polishing degree) and symmetry (symmetry degree) under the cutting grade smoothness (overall decoration degree); The situation of diamond waist generally only provides the size and does not describe it; The situation of the diamond-shaped bottom tip is not described. The details of other diamonds depend on the drawings, which is more intuitive.
IGI five stars ★★★★★★★★ ★:
The highest definition description of IGI certificate is if level to ensure the stability of certificate information. IGI believes that diamond cutting information is the most accurate. The smoothness is subdivided into symmetry, polishing and proportion (the proportion of each part of the diamond), and the details such as the bottom tip and waist of the diamond are also in place.
GEMEX four stars ★★★★★★★★
The traditional 4C defines the rarity and price of a diamond, but 4C information can't distinguish whether the luster, fire color and flash characteristics of a beautiful diamond are superior. Many people may not know that the rarity of a diamond has little to do with its appearance or beauty. If you want to buy the most beautiful diamond, choose GEMEX certified diamond, which allows you to choose the most attractive combination of luster, flame and flash.
HRD Samsung Half ★★★★★☆:
HRD certificates use more descriptive language, such as using phrases such as "white" and "light white" instead of D, E, F, etc. , and the color scale below n is no longer distinguished; In addition, HRD has a fast "diamond identification certificate" for diamonds below 1 carat, and the content information is simpler than its "diamond certificate".
Certificate function information:
GIA four and a half stars ★★★★★☆:
GIA's certificate content is very fixed, and there is little information to provide. If there are special circumstances, such as eight hearts and eight arrows, it will be written in the diamond comment column.
GEMEX four and a half stars ★★★★★☆:
Unlike other traditional certificates, GEMEX certificates measure the 5C-degree-beauty of diamonds. GemEx BrillianceScope analyzer uses patented imaging spectrometer technology to measure the luster (white light), fire color (colored light) and flash (flicker) of diamonds.
By measuring thousands of diamonds in each shape, the highest and lowest amounts of luster, fire color and flash are determined, and the scoring scale of various shapes is set. GemEx certificate includes three bar graphs and five diamond-shaped corner images, which are used to measure optical performance.
IGI five stars ★★★★★★★★ ★:
IGI's special diamond certificate with eight arrows and eight hearts, with eight arrows and eight hearts photos specially taken for diamonds, is a certificate that can display cutting works so intuitively, and its requirements for diamond cutting can be said to be extreme.
IGI can also issue another targeted certificate for diamonds cut and ground by special technology. In addition, IGI is one of the three appraisal institutions that can take laser lettering photos of diamond waist, which adds another guarantee for the correspondence between diamond and certificate. Finally, IGI is also an international certification body for diamonds and jewellery.
HRD four and a half stars ★★★★★☆:
HRD's diamond color certificate focuses on the color grade and naturalness of colored diamonds, which is also a feature.
Certificate style:
GIA is four and a half stars.
IGI five stars ★★★★★★★★★
Four HRD stars ★★★★★★★
There are many types of IGI certificates to choose from. There are only two types of GIA, big and small, and the small certificate does not include detailed charts of diamond defects. There are many types of IGI documents, such as card type (easy to carry), credit card type (not easy to damage) and plastic seal type. , the content is the same, but it can meet different needs.
In addition, GIA and IGI certificates are well-made, and each IGI certificate is hand-made, while HRD's is slightly worse, and there are not many styles to choose from, and the aesthetics are not as good as the first two.
Certificate anti-counterfeiting:
GIA is four and a half stars.
IGI five stars ★★★★★★★★★
HRD four and a half stars ★★★★★☆.
International certificates adopt strict anti-counterfeiting measures, and each certificate has anti-counterfeiting marks of various institutions. The certificate number query on the website can also prove the authenticity of the certificate.
In particular, the plastic sealing service provided by IGI seals the rough diamond together with the appraisal result. From this step, the certificate and the diamond will not be separated from each other, and once the seal is opened, it cannot be recovered, ensuring that the diamond corresponds to its certificate until it reaches the customer.
Certificate cost:
GIA Samsung half ★★★★☆.
The cost of an international certificate is definitely higher, but it is worth it after all. But the appraisal price of GIA is undoubtedly the highest among the three. Moreover, all its appraisal departments are located in the United States, so the round-trip transportation costs are also considerable, and the time cost of appraisal will be high.
IGI four stars ★★★★★★★★
However, there are more than ten laboratories in IGI in the world, so the transportation cost and time cost will be saved, regardless of the appraisal cost.
Four HRD stars ★★★★★★★
HRD and GIA have the same problem. Of course, if you choose the simple version of HRD certificate, the working speed of the laboratory will be much faster, but consumers have to make concessions on the amount of information and accuracy.
Certificate history:
GIA five-star ★★★★★★★★★
IGI Samsung half ★★★★★☆.
HRD Samsung half ★★★★★☆.
GIA was founded in 193 1, long before World War II, while IGI in Europe started diamond appraisal around 1975, and HRD started this service one year later.
General comments:
Gemmological Institute of America.
32 stars
IGI: thirty-two and a half stars
HRD: 29 stars
Other services
With the above information, consumers can choose diamonds with confidence according to their different requirements. For example, an individual pays special attention to a certain factor in diamond 4C, so he should choose a certificate that describes this factor particularly accurately. Moreover, if the requirements for other factors are not too high, the purchase cost of diamonds can be reduced.
In addition, there are some tips when choosing a certificate. For example, only IGI can issue a diamond certificate with a picture of eight hearts and eight arrows on it; GIA can't make diamond inlaid jewelry certificate; Some terms on HRD certificate are different; HRD's "Diamond Appraisal Certificate" is its simplified version and so on. The place where the certificate is issued and so on are all places that need to be recognized at a glance.
Reference link: Baidu Encyclopedia-Diamond Certificate