It is a good idea to buy a diamond with an independent
grading report. Grading reports do not give a value; appraisals do that. They give an independent
expert opinion on quality for loose or unset gems. Most grading institutes have
labs or services worldwide and do not sell diamonds. There can be slight differences in the grades and prices of the same diamonds
graded and priced by different labs.
More GIA diamonds are listed on the internet. IGI and EGL certified diamonds
are common in stores; these labs bundle appraisal and grading services
together. Appraisals go out of date, but unless the diamond is damaged, the
cert is good forever. Store it in a safe place.
Following is a list of common diamond certification labs: