GIA stands for Gemology Institute of America and it is probably the most reputed institute of precious stone evaluating institute. It is an independent body of experts and they give unbiased verdicts on the quality of any stone, including diamonds.
GIA certified diamonds undergo rigorous inspection and quality testing. Then their value and quality are determined. They have a standard process which the institute follows and finally the quality, including clarity of the diamond, is finally settled.
When the diamond arrives at the institute, it is thoroughly cleaned and then they are picked up using a pair of tweezers. It is hold along the girdle of the stone to give the best view to the inspector.
Then the diamond is placed under microscope and illuminated using the dark field lighting. This particular lighting helps the inspector to see the diamond characteristics which cannot be seen using normal lighting.
All GIA certified diamonds are magnified ten times. The inspector zooms in further, if needed, during the rating process, to get a better view. However, the final rating must be done only with ten times magnification.
When the examiner determines the clarity of a jewellery, they are basically looking for flaws and imperfections in the jewellery. When the diamond is flawless or has few flaws, the diamond is considered to be of high value. Please note, there are very few completely flawless diamonds and they cost a fortune. If the stone is plagued with multiple flaws, the value of the diamond goes down.
The first view the examiner takes is the top view of the jewellery, the cutlet area of the diamond. As the stone is held by the girdle, the examiner can view every aspect of the stone easily, from top and bottom.
After the top view is done with, the examiner puts the diamond back and picks it up again, this time, along the ends. This time, the tester checks the facets of the diamond and checks for imperfections or flaws which might be present in the jewellery.
As they go through such a strict set of tests, GIA certified diamonds come with assurance and you can know everything you need to know about a diamond from the certificate the institute issues. It mentions the weight, the size, the value, the known imperfections and the colour of the stone. You will get the best value for money when buying GIA certified diamonds.