A well cut diamond can mean all the difference between brilliance and not so brilliant although this ideal can vary between two different people.

"Well cut" is found in the eye of the beholder quiet often.

People often prefer different proportions to the next person and often there are differences between professionals in the trade also.

Diamond grading, it must be stressed, is not an exact science. Often you can send a stone to three or four different laboratories and get back three differing certificates.

There are several well known laboratories, here is a brief  list:

These are the top main Laboratories of the world with a few more to be added and I can guarantee that you could take a single diamond and send it to all of these Labs

for testing and get back conflicting results, in fact, if you were to send the same stone repeatedly to the same Lab you would get back different answers each time.

The answers will not be  wildly different but would differ in areas such as color or clarity and even cut. A lot of the work done in labs is done with the naked eye but there

is a heavier dependence on computers to map each stone these days so the system for grading is becoming more refined.

Certificates will vary in structure but will have the main themes of the stones in common within each of their content.