ISO 24016 Jewelery and Precious Metals - Grading of Polished Diamonds - Terminology, Classification and Test Methods

The “ISO 24016 Jewelery and precious metals - Grading of polished diamonds - Terminology, classification and test methods” standard developed by the International Organization for Standardization (ISO) describes the terminology, classification and test methods used for the classification and identification of single untreated polished diamonds over 0,25 carats. .

This standard applies to natural, untreated, polished diamonds. It does not apply to fancy colored diamonds, synthetic diamonds, engineered diamonds (except as permitted by this standard) or bonded stones.

The numbering system of jewellery, ring sizes, colors and coatings of precious metals, analysis of diamonds and precious metals, sampling methods and standardization of impurities are included in the "ISO/TC 174 Jewelery and precious metals" standard.

While there are many metals to choose from, jewelry is generally made from precious, high-luster metals such as gold, silver, platinum, titanium, tungsten and stainless steel. Many non-precious metals are gaining popularity in contemporary jewelry to ensure everything from durability to originality.

The purpose of a standard for grading unmounted polished diamonds is to establish rules for determining the mass, color, clarity and cut of individual polished diamonds with maximum precision and accuracy. In the diamond trade, the value of diamonds is determined based on these four criteria, known as "4C". On the other hand, some diamond grading reports may be determined by different laboratories to different standards, potentially leading to different results for the same diamond. Since this situation harms the reputation of the diamond trade, ISO 24016 was designed for the grading of polished diamonds.

This standard is based on recent agreements between the World Jewelery Confederation and international and national diamond organizations to adopt a diamond grading and diamond nomenclature standard. The ISO 18323 standard for grading polished diamonds, together with the “ISO 24016 Jewelery – Consumer confidence in the diamond industry” standard, which establishes the nomenclature of diamonds, synthetic diamonds and diamond analogues, strengthens confidence in the diamond industry worldwide.

For the purposes of this standard,

• Polished diamond refers to diamond with a defined cut.
• Diamond is a mineral created by nature, with a hardness of 10 on the Mohs scale, a specific gravity of about 3,52, and a refractive index of about 2,42, consisting mainly of carbon crystallized in an isometric (cubic) crystal system. Essentially the term diamond always means natural diamond. These two terms are equivalent and have the same meaning.
• Treated diamond refers to a diamond that has undergone any human intervention other than cutting, polishing, cleaning and setting to permanently or non-permanently alter the diamond's appearance. For example, the diamond may be coated, fracture-filled, heated, irradiated, laser drilled, high-pressure and high-temperature treatment, or any other physical or chemical treatment.
• Synthetic diamond is diamond grown in a laboratory environment. It is basically an artificial diamond product with the same chemical composition, crystal structure and physical properties as diamond.
• Composite stone means combined stone. It is a gemstone consisting of two or more pieces.

No matter what base material or method is used, the term diamond alone is not used to describe synthetic diamonds. Products produced in this way are clearly referred to as synthetic diamonds and are not covered by this standard. Composite stones (joined stones) must be clearly identified and are not graded.

Among the numerous testing, measurement, analysis and evaluation studies provided to businesses by our organization, there are also testing services in accordance with the "ISO 24016 Jewelery and precious metals - Grading of polished diamonds - Terminology, classification and test methods" standard.