Advantages of IGI:
1. Cultivated diamonds have a high occupancy rate. Cultivated diamonds are the mainstream and many people choose them.
2. The international authority certificate will indicate whether it has been changed.
IGI Disadvantages:
1. Indian certificates are easy to downgrade, and the cheap ones on the market are basically Indian certificates.
2. Indian certificates pretend to be Shanghai certificates and Hong Kong certificates.
Advantages of NGTC:
1. The audit standard is the most stringent organization in the country, with high standards, so you don't have to worry about relegation.
2. The content of the certificate is marked in Chinese, which is clear and clear.
NGTC Disadvantages:
1. The remark is not detailed, and will not mark whether there is a color change.
Advantages of GIA:
1. The review standards are relatively strict. The mainstream certificates in natural diamonds and cultivated diamonds also have GIA certificates with blue and white covers.
2. Strong credibility.
GIA Disadvantages:
1. The price is generally higher than other certificates
2. There is only one voucher and an electronic version of the certificate. The merchant needs to print the paper version by himself. This is where the problem lies. It is easy to be taken advantage of by unscrupulous merchants who make a set of certificates. Mosang will also give you a GIA certificate.
NGIC Gold
For local institutions, the testing standards are relatively loose, and they will be downgraded. You can choose if you want high cost performance.
NJC (nftc) head of state
Local institutions, standards are passable.
CTI
Local institutions with strict standards are rare on the market.
GEM
It is equivalent to the English version of NGIC and will be downgraded.