Articles about Diamond Grading
To the naked eye a D Flawless diamond can appear identical to an F VS diamond if each has been cut the same way. Alternately, less than one degree of variation in two diamonds’ facet measurements can make a noticeable difference in appearance - yet both could be issued the same cut grade from a given lab.
Consumers’ Problems and a Solution
By Sergey Sivovolenko, Janak Mistry, Garry Holloway and Dr Yuri Shelementiev
On many websites you will see it said that the pavilion main facets drive light return. Top labs and many grading systems use the pavilion angle as a basis for assigning a cut grade.
Is this correct?
Intended to gauge the credibility of represented color, clarity and cut grades compared to GIA or AGSL grading.
Highest Confidence: SCORE = 1
The grade will exactly match GIA/AGS 65% to 70% of the time. This is about the level at which these lab’s own graders match each other’s grades while working on diamonds. This grade ONLY applies to loose diamonds. Only very highly experienced, properly trained and equipped graders can claim this level of confidence. Very few gem laboratories or gemologists actually have this degree of competence.