The NGTC certificate is issued by the National Jewelry and Jade Quality Supervision and Inspection Center and is a very authoritative national diamond grading standard. Before the change, the NGTC standard was definitely higher than the GIA appraisal standard, and now it is stricter than GIA.

NGDTC certificate is issued by the National Gold and Diamond Products Quality Supervision and Inspection Center.

Recommend NGTC.