(IDEX Online) - International standards are to be introduced on the grading and classification of diamonds under 0.25-cts.The Swiss-based ISO (International Organization for Standardization) has already specified the terminology, classification and methods to be used for the grading and describing single unmounted polished diamonds above that size.The World Jewellery Confederation (CIBJO) says agreement on such standards will be "a truly historic accomplishment".Jean-Pierre Chalain, its diamond commission vice president, is convener of the working group overseeing the project."It is an undertaking of enormous consequence, with significant technical challenges," says CIBJO."The output of smaller polished diamond not only is considerably larger in carat terms than the output of larger goods, but also in terms of monetary value. "As is the case with larger diamonds, the quality of a small diamond is defined by its 4Cs???,? ?. But small diamonds are often sold in homogenous batches. And, when this is the case, quality control by sampling is considered acceptable."Generic pic of melee diamonds