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A JTR Jewellery Report is the assurance that the article is inspected by a laboratory that is objective, responsible, transparent, and trustworthy

What grading standards does JTR’s diamond grading laboratory apply?

Diamond ring and loose diamond
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.

Single set of rules for describing diamonds

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.”

Diamond laboratory accredited by ISO 17025

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.

Grading principled based on IDC Rule Book

The IDC was founded in 1975 by the World Federation of Diamond Bourses  (WFDB) and the International Diamond Manufacturers Association (IDMA). JTR recognises that the IDC and its Rule Book are the flesh and blood of the global diamond industry and trade. Therefore, JTR’s laboratory and diamond graders follow the IDC Rule Book.

About ISO Standards 18323 & 24016

In 2015, IDC and its officers were instrumental in creating ISO standard 18323. This standard was necessary to ensure that consumers understannd the difference between natural diamonds and synthetic or laboratory-grown diamonds (LGDs). JTR adheres diligently to this standard.

In September 2020, ISO (the International Organization for Standardization) published ISO Standard 24016: 2020(en). “This document specifies the terminology, classification and the methods that are used for the grading and description of single unmounted polished diamonds over 0,25 carat.” These three publications - the IDC Rule Book, the CIBJO Diamond Book, and ISO Standard 24016 - are harmonised.
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Advanced diamond grading laboratory

Enjoy peace of mind as you appreciate the beauty of your diamonds with an JTR diamond grading report. Our innovative and comprehensive analysis will ensure you know exactly what you paid for – as they say, the devil is in the details.
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