A diamond certificate,also known as a diamond grading report,or a diamond quality report,is based on the 4C standard for diamonds and is carefully considered by jewelers in a specific environment based on strict grading standards.A report formed by observing and testing diamonds.It is an important part of analyzing the size,clarity,cut,polishing,and symmetry of the diamond under a ten-fold magnifying glass.It also includes determining the color level of the diamond,fluorescence detection,etc.

　　Common diamond certificates

　　1.International certificate

　　GIA

　　Gemological Institute of America is an independent,not-for-profit organization.The Academy's groundbreaking research and its own education,experimentation and equipment development process have witnessed the chronicle of the growth of the jewelry industry.

　　GIA has created the diamond 4C grading system that has been used to date,bringing diamond identification to the founder of internationalization.As the standard setter,GIA is absolutely the most accurate in controlling the 4C grading standard.

　　The GIA Diamond Grading Report and GIA Diamond Processing are considered to be world famous gemstone certificates.Diamonds of all shapes and sizes are sent to the academy for analysis and grading from all corners of the world.

　　IGI

　　International Gemological Institute is the largest independent gemological identification laboratory and gemological research and education institution in the world.It has 15 laboratories and schools in major diamond trading centers and central cities around the world.Gemologists from more than 96 countries around the world accept IGI.Laboratory and educational research services.

　　Extensive experience,professional advice and long-term reputation for integrity have made IGI a synonym for reference standards in the jewelry industry.IGI has developed patented technologies such as laser marking and darkroom photos for decades,and has promoted the 3EX cutting evaluation system.It has long been a global leader and specification maker of gemology.

　　HRD

　　The HRD certificate mainly takes the shape,size and weight of the diamond as the main data for strict measurement,and especially makes more detailed measurement report on the cutting ratio.

　　The HRD diamond color certificate focuses on the detailed characteristics that determine the value of colored diamonds,such as color description,color design,and luminescence.It plays an important role in determining whether the diamond is a natural colored diamond or a imitation diamond.

　　EGL

　　EGL's clients focus on professional wholesalers,retailers and cutting factories,with the mission of helping consumers buy diamonds and precious stones.EGL certification in the United States and Belgium has a certain professional status and popularity.The certificate issued by it is sufficient to provide all information about the diamond,including its weight,color,clarity,size and other physical properties,for reference by the industry and consumers.

　　2.National certificate

　　NGTC

　　NGTC is a certificate issued by China's national nature and the founder of China's first diamond grading standard.For the NGTC certificate,it is not only for the inspection of loose diamonds,but also for the finished jewelry with diamonds such as diamond bracelets.

　　GIC

　　China University of Geosciences established the Gemological Research Office in 1983.In 1989,it developed the Gemological Institute of the secondary institution.In 1992,it was approved by the Ministry of Geology and Minerals to establish the Jewelry Institute.In 1993,the Jewelry Testing Center was established.The center focuses on identification,consultation,training,exhibition,production and processing,and serves the society extensively.

　　With the improvement of CVD synthesis technology,through the adoption of gas raw material(hydrogen,methane),Luoyang Yuxin Diamond Co.,Ltd get the completely transparent and colorless large size diamond single crystal under less than one air pressure,the temperature of 800-1200℃by epitaxial growth way(growth way/as shown in Figure 1),its composition,hardness,density,etc.are basically identical with natural diamond,but the price is much lower than that of natural diamond;different from the method of high temperature and high pressure(HTHP),CVD artificial synthetic technique does not need to use the catalyst,and puts an end to forming metal inclusions,cracks,holes,etc.in the production.

　　Features:after polishing,the clarity is commonly VVS and above level,color chromaticity of D-J.

　　We can provide raw diamond at carat level.