Why does a diamond cost more with a GIA Certificate?
GIA is the most widely respected diamond-grading laboratory because they are conservative in their grading. The better quality diamonds are submitted to GIA. Lesser quality diamonds are submitted to other labs like EGL or IGI. They may grade an H color diamond as a higher G color, or an SI-1 may be considered a VS-2. Besides respectability, the GIA cert costs more to get than other certs, so it is included in the price of the diamond.
