JTR’s management, staff, and gemmologists all adhere to the baseline of the Rule Book of the International Diamond Council, or IDC Rule Book. IDC’s grading standards and nomenclature result from many decades of arduous work by, often unnamed, international diamond experts.
Standing on these experts’ broad shoulders, the Diamond Commission of CIBJO (The World Jewellery Confederation), then created the CIBJO Diamond Book. In 2017, IDC and CIBJO harmonised the IDC RuleBook with the CIBJO Diamond Book, “creating a single set of rules for describing diamonds.”
JTR’s diamond grading laboratory is accredited by the ISO with standard ISO/IEC 17025
. “ISO/IEC 17025 General requirements for the competence of testing and calibration of laboratories is the main ISO standard used by testing and calibration laboratories. In most countries, ISO/IEC 17025 is the standard for which most labs must hold accreditation in order to be deemed technically competent.” In other words: a laboratory’s accreditation with standard ISO/IEC 17025 guarantees that the results generated by a laboratory are responsible transparent, and trustworthy.