A report that ignores standards offers no assurance.

Diamond grading means something only when technical skill is matched by adherence to international standards. Without standards every laboratory applies its own criteria, results stop being comparable and the consumer is left unprotected.

Accreditation

IAS accredited laboratory

JTR Gemology Grading Laboratory is accredited by the International Accreditation Service (IAS). That accreditation independently confirms the competence and impartiality of our grading processes. What it means for you: JTR reports can be trusted with international validity.

ISO/IEC 17025 aligned IAS accredited IDC compliant
IAS Accredited — Management Systems Certification Body

IAS Accredited laboratory

ISO 17025 Certified

ISO - 17025 Testing competence

IDC — International Diamond Council

IDC Grading rules

Recognised worldwide — world map

Global Recognized worldwide

Our commitments

The three conditions of trustworthy grading

Independence

Graders work without knowing the commercial value of the stone or its owner. Bias cannot enter any stage of the process.

Controlled conditions

Standardized lighting, calibrated instruments and documented methods are applied to every stone under the same conditions.

Traceability

Laser inscription and a digital record system link each stone to its report for life.

The IDC, CIBJO and ISO framework

What our standards are built on

JTR’s grading procedures follow the rule book of the International Diamond Council (IDC), founded in 1975 by the WFBD and IDMA. In 2017 the IDC and CIBJO diamond books were brought together under a single framework, giving the global diamond trade one common language.

JTR holds ISO/IEC 17025 accreditation. It confirms, through an independent body, the technical competence of the laboratory, the reliability of its measurement results and the effectiveness of its quality management system — the highest recognised competence standard for testing and calibration laboratories worldwide.

ISO 24016:2020 defines the terminology and methods used in diamond grading, while ISO 18323 sets the product description and labelling rules that protect consumer confidence in the jewellery industry. Together they govern both what a report says and how it says it.

For you, compliance is a concrete assurance: every JTR report is produced by internationally accepted methods, so results are repeatable, comparable and auditable. Standards protect the value of your diamond.