Diamond Grading

International Diamond Laboratories writes:
The biggest issue with diamond grading as we know it today is inconsistency. A diamond that is awarded an E color grade might receive a D tomorrow and an F the day after. Our research has shown that inconsistency easily reaches up to 25% on average. It’s merely a simple fact related to the imperfections of the human eye as a measuring instrument. Experienced graders will acknowledge that these differences exist. A machine can overcome this subjectivity. IDL commits to offering a level of consistency the diamond market has not yet seen. Diamond grading is to be brought from an art to a science. IDL will offer the much needed consistency through technology. (http://www.diamondlab.org)


Useful link:
Hughes, R.W. (1987) Diamond grading: Does it work? Gemological Digest, Vol. 1, No. 2, pp. 1–3

In my view diamond grading will always be controversial. A friend of mine who is in the business tells me that diamond grading is a faith-based concept. We have got used to it for so long it's going to be with us forever. So now comes the International Diamond Laboratories' statement (s) that their version is more scientific, fool-proof, sort of a god-like statement. Only time will tell. In the end it's the consumers who will have to raise their standard (s) by gaining appropriate skills to distinguish (which I doubt) diamond grades and believe it. When experts /technology go wrong (they usually do), consumers are always the losers.