What is Diamond certification?

A Diamond certificate can be known by several different names, such as “Diamond grading report”, “Diamond Dossier”, and “Diamond Quality Document”. Despite the name, these documents will try to give a report on the overall quality of a Diamond, however not the value.
Diamonds now tend to be graded using a system first employed by the GIA (Gemmological Institute of America), this being the rating of colour, cut, clarity and carat weight (known as the four C's). Carat weight and cut of stone are factual representations, which can be measured and do not rely upon personal opinion. Colour and clarity are more subjective in their grading and are dependant upon the master set of grading stones, held by the certification body and the eye and opinion of the grader. Here is an overview of these four grading categories and how they are scored.